156 DE. A. D. IMMS ON THE 



the idea of their being regarded as teeth in the ordinary acceptance of the term. It is 

 difficult to conceive what purpose, if any, they may fulfil. They are perhaps to be 

 regarded as enlarged and slightly modified papillae of the same type as tbose found on 

 other parts of the body. The dentate spines are larger and much more numerous than 

 in the young larva. In coloration it is similar to that of the full-grown larva to be 

 described below. 



C. The full-grown Larva. — Examples of the full-grown larva varied in length from 

 6 - S-7"2 mm., with a width of 8'5 mm. across the widest part of the body. The head 

 and jaws are yellow-brown, the latter being a little darker at their extremities. The 

 dorsal surface of the head has a granulated appearance produced by the numerous 

 dentate spines scattered over it (PL 32. fig. 3). Between the eyes there is a pair of darker 

 brown patches, and on them open a pair of cbitinous tunnels which are directed into 

 the head. Each eye-group is placed on a rounded tubercle on either side of the head. 

 The first segment of the neck is buff-coloured, the second segment is darker and 

 inclining to brownish towards the base. The trunk-iegion is light brown, darkening 

 towards the mid-dorsal line. The brown coloration is disposed in a series of transverse 

 segmental bands, whose width narrows towards the outer margins of each segment. A 

 median longitudinal streak of buff-colour runs down the whole length of the trunk- 

 region, except in the third segment, where it is crossed by the transverse brown band of 

 that segment. The outer margins of each segment are suffused with buff-colour, arid 

 the buff-coloured longitudinal streak is bisected by a narrow brown line extending from 

 the fourth to the seventh segment. The terminal papilla-like apical segment of the 

 body is buff-coloured, and the legs are pale brownish. Ventrally, the head and jaws are 

 of the same colour as exhibited on the dorsal aspect ; the first segment of the neck and a 

 large portion of the second segment are buff-coloured, while the rest of the body and 

 legs are light brown. 



The table of measurements on p. 157 shows the relative growth of the different 

 regions of the body during three periods in the life-history of the larva, 



The Habits of the Larva. — A number of larvae in all stages of development were reared 

 in captivity, and they fed upon Psocids and very young larvae of a species of Dermestes ; 

 they are exclusively carnivorous. The process of feeding was observed under a Zeiss 

 binocular microscope in the case of a larva confined within a small glass vessel for the 

 purpose. The prey is seized by the tips of the mandibles and held there until its juices 

 are completely sucked out by the pumping-action of the pharynx. The maxillae (PI. 32. 

 fig. 4>) resemble the mandibles very closely in shape and size, and fit into the underside of 

 the latter, which is grooved to receive them. An imperfect channel is thus formed by the 

 mandibles and maxilla? on either side, and the juices of the prey were easily observed to 

 pass down it to the head, and afterwards down the oesophagus in the neck. The neck 

 is very flexible, and consequently the head has considerable latitude in its movements. 

 On one occasion I noticed a Psocid crawl on to the back of a Croce larva, and the 

 latter bent its head and neck completely over its back with great ease and seized it. 

 The adaptation of the mandibles and maxillse to form an imperfect suctorial tube has 

 been previously observed among other subfamilies of the Hemerobiidse, notably by 



