151 



having the anterior abdominal segments rather less thictly punctured, and the fifth 

 segment somewhat sparingly punctured. 



The head in bulk is very nearly equal to the thorax, and the part behind the 

 antennae is nearly square, but a trifle broader than long, and has the angles rounded ; 

 the upper surface is depressed, rather more so in the male than in the female, and 

 has a faint longitudinal groove; the surface is most indistinctly punctured. The 

 antennte are uniformly fuscous, and when compared with those of H. gregaria present 

 no appreciable diflference. The thorax is nearly quadrate, but slightly contracted 

 behind ; it has a shallow transverse fovea behind, and a shallow longitudinal depressioa 

 extends forwards from this to the middle of the thorax ; in the male is a distinct dorsal 

 channel, extending to the front of the thorax ; 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 t'lie 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 genus 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 

 Hearly 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 one 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. Hydrnpsyche ophthalmica, 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 ? colurabina, Pictei. Taken by Mr. Wormald at Llangollen, 

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

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

 occipitalis, Pict. (Apelocheira subaurata, Steph.), 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 desp notch in the middle of the 

 upper margin, which is absent in H. occipitalis. 



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