188 Young Larvae o/Lyctus brunneus Ste^jh. 



cylindrical and its body is straight and not arched as the later instars 



a 



are' 



The following description is based on specimens mounted in balsam, 

 or glycerine. 



The head (Text-fig. 1, 2 a) is broader than thick and is circular viewed 

 dorso-ventrally. It is partially enveloped by the pro-thoracic folds. 

 There are a pair of rudimentary eyes (e) composed of pigmented spots 

 and situated below and posterior to the antennae (a). No consistency in 

 the shape of the eyes was observed, the number of pigmented spots vary, 

 the majority are in juxtaposition, but a few are some distance apart, 

 and they are deep purple in colour. 



(Eyes were found on the larva of each instar^. Duges [1883] in his 

 description of — apparently — the full-grown larva of L. carbonarius, refers 

 to a pair of protuberances which he considered to be eyes, and which he 

 figured between the mandibles and antennae. This position differs from 

 that of those of brunneus.) 



The antennae (Text- fig. 1, 2 b) are telescopic and are situated in recesses 

 and consist of one basal joint (b) and two apical pieces {a^, a^). One apical 

 piece (a^), which is the antenna proper, is wider at its apex than its base 

 and terminates in two minute fleshy protuberances, towards its base is 

 a sensory pit. The other apical piece (a^) is venter and is longer than the 

 dorsal piece. (A ventral apical piece has been found venter to the apical 

 joint of the antenna proper in every instar^; in the later stages it decreases 

 in size in an inverse ratio to the size of the apical joint of the antenna, 

 until in the full-grown larva it is barely one-sixth the length.) 



The mandibles (Text-fig. 1, 3) are of the same type in each instar and 

 are of a pecuHar structure. The molar or distal joint (mr) is roughly tri- 

 angular in outline dorso-ventrally; it is tridentate (Text-fig. 1, 3 iv). 

 Situated dorso-posteriorly and above the molar is an extended dorsal 

 condyle^, which terminates in a small rounded structure [or) serrated on 

 its inner lateral face ; and arising from the outer lateral face of the serrated 

 structure, is a group of chitinised setae (br), which are curved round the 

 posterior border to the inner lateral face (Text-fig. 1, 3 m). This extended 

 dorsal condyle which does not appear to bear any relation to the movable 

 prostheca of Kirby and Spence (Packard, 1909), is situated at the end of 

 the hypo-pharynx. It comes into operation when the molars are opened 



^ Gahan (1920) in describing the first instar larva of Anobium putictatum De Geer 

 states: "At this time they are... straight-bodied, instead of having the body strongly 

 curved as in the older larvae;...." This similarity between these first instar larvae of these 

 systematically closely related beetles, is of some interest. 



2 This is not mentioned by Monro (1915-16) in a description of the full-grown larva. 



