Twenty-four West Indian species of this genus were enumerated in Messrs. Leng and Mutchler’s list of 1914, in addition to which four species from Porto Rico have since been named by Mr. Eugene Smyth (Journ. Dept. Agric. Porto Rico, i, 1917). Two other species have been assigned to the genus Phytalus, which is distinguished from Lachnosterna solely by the claw-tooth making an acute instead of a wide angle with the tip. As H. W. Bates found in his attempt to distribute the Central American species, it is impossible to make this the basis of a natural division, especially as in certain species (as in L. dilemma here described) it is confined to the male.

Most of the following observations were made in the vicinity of Obozerskaya, a small village on the Archangel-Vologda Railway, 474 versts from Vologda or roughly 80 miles due south of Archangel. I arrived at Obozerskaya and reported to the Headquarters of the Vologda Force on 14th June 1919, a few days after disembarking at Archangel.

Having received from the Imperial Bureau of Entomology more material of the family LONCHAEIDAE, I am in a position to give the following additional notes to my previous paper* on the Ethiopian species.

In the introduction to the first part of this paper* it was remarked that very little exact work had been published on the adult European SIMULIDAE. This is equally true of the larvae and pupae ; in fact no one has attempted to describe the early stages of more than two or three of the common species. Moreover, in spite of their great interest, and the ease with which they can be collected and reared, they have apparently been almost entirely ignored by collectors, so that whereas in publishing my previous work I was able to acknowledge valuable assistance from a number of fellow entomologists, the results given in the following pages are, unless otherwise stated, due to my own observations. I wish especially to thank Mr. M. E. Mosely for the early stages of S. subornatum, the last species to come under my notice in the pupal stage. While there are still many important gaps in our knowledge which remain to be filled, it has been thought worth while to state without further delay the results that have been obtained so far.

The occurrence of mosquitos in crab-holes is tolerably well known both in West Africa and in other countries. It is doubtful, however, whether these sources receive sufficient practical attention, and one hears too often when their presence is demonstrated the opinion expressed that the insects only shelter there and are not likely to use them as breeding-places when so many others are available. One has even found medical officers whose unbelief had to be assailed by demonstration of the larvae and pupae. Others again, though aware of the fact, perhaps think the occurrence of too trifling importance to justify the necessary steps to eradicate them, even when near a dwelling.

Colour piceous black ; the head with dark brown scaling above, except for a line of pale scales bordering the eye, and with pale buff scales beneath ; scaling of the prothorax brown or grey brown on the disk, an ill-defined dark brown stripe at the side, and grey or buff beneath ; scaling on the elytra grey or brown, with a very ill-defined darker stripe between striae 2 and 5, usually vanishing at a short distance from the base, but often traceable to behind the middle in the form of spots.

On 12th September 1919, while watching at a pool near Kotakota, Lake Nyasa, the emergence of mosquitos from their pupae, which in the case of this particular species takes place mostly between 4.30 p.m. and dusk (about 6.30 at that time of year), the writer saw at rest on some scum on the surface of the water, an Anthomyiid fly of the genus Lispa, which after a few minutes made a sudden rush at a mosquito just emerging from its pupa-case. The mosquito with its wings still unexpanded and part of its legs and the hinder segments of its abdomen still within the pupa-case was absolutely at its mercy. The fly grappling it from behind with its front legs proceeded to thrust its proboscis into the thorax. The fly was by no means timid, and it was possible to lean over and approach one’s head to watch the proceedings so closely that it was even possible to determine by its antennae the sex of the unlucky mosquito ; it was a male. The fly was captured before it had finished its meal, lest it should suddenly fly up and escape.

The “cyanide bottle” is never a very attractive part of the entomologist’s equipment. When made up in the old way, i.e., plaster of Paris poured over lumps of solid potassium cyanide and the plaster then allowed to set, the contrivance has an attractive appearance, but is an abomination to use, especially if small insects are being dealt with. The large amount of water utilised in making up the plaster of Paris can never be dried out properly, and the potassium cyanide being deliquescent to some extent the presence of moisture is unavoidable. Moreover the cyanide soon decomposes and turns brown, imparting its colour to the plaster and forming an ugly-looking mass on which small insects, are not contrasted and may be easily overlooked and lost.

In the summer of 1918, there was every prospect of an unusually good crop of dates in Mesopotamia, until the month of June, when a large number of the half-grown dates suddenly became “hashaf” — an Arabic word signifying that they dried up and fell from the trees. This was a very serious matter, not only because the date is the principal resource of the country, but also because any and every disaster was at that time attributed by a section of the population to the British administration. At the end of July I was lent to the Directorate of Agriculture to carry out an investigation upon the failure of the date crop. I found that the principal pest, the larva of a Gelechiid moth, had finished its work, and had wandered away from the palms to pupate ; and though I was unable to solve the problem of its life-history, I had the good fortune to discover a good deal that was new about the insect pests of the date palm. At the time I published a report (1918), to which I only refer now in order to say that it was produced on the spot and without access to any books ; it contains certain inaccuracies, and anything of value which I may have discovered will be found in the present paper. During the course of my investigations I visited all the important date-growing areas of Mesopotamia, that is to say, Baghdad and its neighbourhood, the Diyala River from Ba’qubah to the Persian Frontier at Baba Pillawi, Mendali and Balad Ruz, Basra and the country round it, Mohammerah and Fao, the Lower Euphrates from Nasiriyeh to Suq-ash-Shuyukh, Qurnah and Amara. At the time of my visit the fruit was nearly ripe, so that it was not difficult to learn the distinctions between the different varieties of date palms, a point of great importance in view of the fact that they are liable to the various pests in varying degrees. I strongly recommend future investigators to familiarize themselves throughly with these varieties, and also with the very considerable number of Arabic words which are used specially for the date palm and its cultivation. This is no small task, as will be realized when I mention that in Mesopotamia about 70 words are employed by the peasants for various parts of the date palm ; the vocabulary relating to cultivation and methods of employment is just as extensive.

The following notes may be regarded chiefly as materials towards the study of the geographical distribution of this group of the bloodsucking midges, which are of so much interest from a medical standpoint. For the opportunity of examining the very large series of specimens (570) herein recorded, I have to thank Dr. Guy A.K. Marshall, Director of the Imperial Bureau of Entomology, who sent the collections made by Drs. A. Ingram and J.W. Scott Macfie, in the Gold Coast ; and also that formed by Capt. J. Waterston, R.A.M.C., in Macedonia. I tender my thanks also to Capt. P.A. Buxton, R.A.M.C., for the collections made by him at Amara, Mesopotama ; to Capt. H.W. Leatham, R.A.M.C., for examples from Basra ; and to Major J.A. Sinton, V.C., I.M.S., for the specimens which he collected in N.E. Persia, under exceptionally difficult circumstances, and also for the long series taken by him in the N.W. Frontier Province of India.