8668 Entomological Society. 



channel, extending to the front of the thorax j the surface is very thickly and finely 

 punctured. The elytra are but little longer than the thorax, but nearly one-third 

 broader; they present scarcely any gloss, being very thickly and finely punctured, and 

 having a correspondingly fine and dense pubescence; they are fuscous at the base, 

 and gradually assume a paler hue towards the apex. The abdomen is glossy, some- 

 times pale at the apex. The legs are slender, as in H. gregaria, but rather longer. 

 The tarsi are elongate, and in those of the hinder legs the first joint is pretty distinctly 

 longer than the following three joints, as in the insect last mentioned, and which no 

 doubt induced Erichson to describe it as a member of the geuus Tachyusa. 



"The sixth abdominal segment in the male is furnished with a small laterally com- 

 pressed tubercle, and the terminal segment has the middle portion of the upper plate 

 produced and terminating in four denticles, of which the middle pair are approximated 

 and most prominent; the external pair are slightly obtuse, and are separated by a deep 

 nearly semicircular notch from a spine forming the outermost lateral boundary of the 

 plate, and the apex of which terminates nearly on the same plane as the outer pair of 

 denticles. 



" I possess five specimens of this species, four of which were taken in the corridor of 

 the Crystal Palace, and the fifth was found by one of my sons in the court yard of the 

 British Museum. Two of these are males : in one of the males, and in one female, 

 the thorax presents on its disk a large and tolerably deep oblong impression, as is fre- 

 quently seen in H. gregaria and some other species. In oue specimen both thorax 

 and elytra are palish brown, perhaps from immaturity." 



Mr. M'Lachlan exhibited three new British species of Trichoptera, on which he 

 read the following notes : — 



"1. Hydropsyche opblhalmica, Rambur. Taken by myself, 1 believe between 

 Kew and Richmond, and by Mr. Wormald at the same place. Readily distinguish- 

 able from all other described species by the large size of the eyes in the male, the 

 vertex from this cause being almost quadrangular. Kindly determined for me by Dr. 

 Hagen, who has seen Rambur's types. 



"2. Philopotamus ? columbina, Pictet. Taken by Mr. Wormald at Llangollen, 

 North Wales, in September, 1862, and by myself near Bickleigh, Devon, in the same 

 month. This is not a true Philopotamus, belonging to the same group as Hydropsyche 

 occipitalis, Pict. (Apelocheira subaurata, Sleph.), and closely allied to that species, but 

 differing in its slightly smaller size and darker colour, and by the structure of the 

 last abdominal segment in the male, there being a deep notch in the middle of the 

 upper margin, which is absent in H. occipitalis. 



"3. Psychomia (Homoecerus) derelicta (n.s.). I propose this name for an insect 

 belonging to a rather obscure group, and which I cannot make out to have been pre- 

 viously described; a specimen sent to Dr. Hagen last year was returned as unknown 

 to him. It belongs to a group mentioned by Dr. Hagen in the ' Stettiner Entomolo- 

 gische Zeitung' for 1860, p. 279, differing from the true Psychomia? in the broader 

 and more obtuse wings, in the more widely dilated intermediate legs of the female, 

 and especially in the possession by that sex of a rather long and curved ovipositor ; 

 nevertheless Dr. Hagen thinks that the proper place of the group is with Psychomia. 

 Kolenati, in the second part of the ' Genera et Species Trichopterorum,' places it as a 

 subgenus of Tinodes, which he calls Homoecerus, a position it can scarcely retain, as the 

 females cf Tinodes have undilated intermediate legs. Kolenati describes four species under 



