40 [February, 



the terra is for them (as well as for the other Hydropsychid larvse which want tra- 

 cheal branchiaB) exceedingly appropriate. They are rather slender, cylindrical, their 

 segments of nearly uniform breadth, save that the head, prothorax, and ante-penul- 

 timate segment are rather, and the last segment much, narrower. The head (apart 

 from the trophi) is a short oval, a little depressed, clypeus truncate anteriorly ; eyes 

 placed very near the front and just above the sides; antennae consisting of a 

 hemispherical base carrying a long hair and two short ones (at least I consider these 

 represent the antennae from the position they occupy). Labrum broadly elliptical, 

 anterior margin slightly excised, eight marginal and two discal bristles or hairs, a 

 fringe of hairs on either side of the excised part, which part is densely ciliated with 

 very short hairs placed inferiorly. Mandibles, in situ, irregularly triangular in outline ; 

 right seen from above has two teeth below tlie apex on the upper edge and three on 

 the lower ; between the two edges is a fringe of hairs ; in the left the teeth are not 

 so numerous or are less distinct ; two hairs or bristles on the back of each mandible 

 (the details of the teeth are especially applicable to T. aureola ; T. wceneri presents 

 slight differences, but the general aspect of tlie mandibles is alike in both species). 

 Maxillje large and broad, apex closely beset with short hairs and bristles or bristle- 

 like processes, a pencil of long hairs on the inner margin, a bristle on the under-side 

 about the origin of the palpi ; these are four-jointed and tapering, the first two 

 joints short and about equal in length, the third double the length of the preceding, 

 and the fourth smallest of all. Labium with two sub-quadrate basal plates, each 

 bearing a bristle ; a bristle at each side ; spinneret of great length and slender, 

 tapering to a point. 



Prothorax (which, like the head, is chitinous, and very sparsely beset with long 

 hairs) transverse, hardly broader than the head, narrowing sliglitly posteriorly. 

 Pronotum straight in front, hind angles rounded : prosternum small, running into a 

 point between the fore legs. The other thoracic segments are not chitinized, but 

 are like the abdomen. The legs are short, sub-equal ; anterior pair much the 

 strongest, and perhaps just a little longer than the others, from which the fore-legs 

 differ in having the tarsi ciliated ; claws of all the pairs with a short basal spine, 

 and in the hollow between it and the claw there is a single hair. The tibiae also 

 bear a spine or two, and the whole of the legs bear a few scattered haii's. Articu- 

 lated to the coxse of the first pair of legs in all the campodeoid larvse that I have 

 seen, is a process which is usually long and slender, but which in Tinodes is rather 

 broad. 



The segments of the abdomen are distinct. The anal limbs are of moderate 

 length, two-jointed, a short basal joint, and a long joint bearing at its apex above a 

 pencil of about six very long and strong hairs ; attached to the under part of the 

 apex of the second joint is tlie strong claw which also carries a number of small 

 hairs, and on its under-side (in T. wceneri) five or six sharp teeth. The anal filaments 

 are five in immber (in T. wceneri ; number not ascertained in T. atireola, but probably 

 the same), two lateral pairs and a single median filament. These filaments are of 

 great interest and importance, as Fritz Miiller is of opinion that they are alternative 

 breathing organs and function as true branchiae (" Blutkicmen "), like those of the 

 stalk-eyed Crustacea, and not in the same way as the lateral filaments found in most 

 Ti'ichopterous larvae {vide Ent. Nachrichten, 1888, pp. 273 — 277). 



The following notes refer to the colours of the larvae of the two 



