Parnus.] CLAVicoRNiA. 383 



(P. lutidryitus, Er. This species has found its way into some of our 

 lists, but does not appear to vest on sufficient autliority ; it is oblon» 

 and somewhat drpre^^sed, black, oldtlied with very thick yellowish 

 pubescence interminglt-d with short grey hairs, and may be reco'jnized 

 by the rows of punctured strise on the elytra, which are feeble but 

 regular, and tracealjle to apex ; the species is much larger tliau P. 

 algi'Hcus, the striation is weaker, and the pubescence is yellower. L. 

 4-4| mm.) 



HETEROCERID^. 



Tins family consists of a single genus, Heterocerus ; its true position 

 is somewliat doubtful, as it does not appear to bear a very marked 

 affinity to any particular family ; in their amphibious and subaci^uatic 

 habits the species n semble the Parnidce, and in their densely pubescent 

 surface, very short anteimat:, and general shape are not unlike certain 

 species of Partius. aUhough they differ entirely from them on a closer 

 examination ; perhaps, however, taking all things into consideration, it 

 is best to place them near the Parnida?^ and, as an aberrant family, 

 they may be with advantage placed at the end of the Clavicorn series ; 

 the iollowing are the chief characteristics of the family : head large, 

 front prominent, antennae sliort, inseited above the base of the man- 

 dibles near the inner margin of the eyes, 11-jointed, with the two first 

 joints large, and the remainder forming an oblong serrate club; eyes 

 half hidden by the thorax ; thorax tiansverse, with the sides at most 

 margined only behind, free at base, and not fitting closely to elytra, 

 with all the angles rounded ; anterior coxal cavities open behind ; 

 mesosternum very short, metasternum moderate ; elytra covering abdo- 

 men ; abdomen composed of five segments, of which the last two are 

 free and the others connate ; legs fussorial, tibia? dilated and armed 

 with spines, tarsi short, 5 jointed, according to some authors 4 jointed, 

 the first joint being very minute (and so, often overlooked), capable of 

 being folded back upon the tibiae when these are used for digging ; 

 anterior coxae transverse with distinct trochantin, posterior coxae nearly 

 contiguous at base ; on each side of the first segment of the abdomen 

 is an elevated curved line reaching the posterior margin ; this elevated 

 line is finely striate transversely, and according to Dr. Horn is a stridu- 

 lating organ, the hind legs by friction against it producing quite a 

 distinct sound. 



The larva of Heterocerus is fi ^ured by Westwood (Classifie. i. p. 113, fig. 7, 5) ; 

 it is quite as anomalous as the perfect instct, and most resembles an inverted 

 teetotum ; the head is large, with strong toothed mandibles, behind which the eyes, 

 which are small, are situated ; the three thoracic s^egments are abnormally large, 

 nearly twice as broad as the head, and very transverse ; the abdominal segments are 

 nine in number, aiid very much narrower than tlie tliora<ic segments, the last being 

 longer than the rest; they are slightly njirrovvtd towards apex, and are subcylin- 

 drical ; the body is strongly setose, and the legs are stout and strong, and armed 

 with a single claw ; the larva occurs in the same situations as the perfect insect. 



