1915. | F. H. GRAVELY: Beetles from Cochin. 361 
rather to some species of Lycus. To this genus—which has since 
been subjected to extensive subdivision—he was also inclined to 
refer the slender parallel-sided insect of the ‘‘ Trilobite’’ group, 
which he was the first to notice and figure. 
Erichson accepts these insects as Malacoderms, but in spite 
of their weak mandibles regards them, because of their shape 
and because the head is completely retractile, as Lampyrids 
rather than Lycids. Candéze agrees with Erichson; but Kolbe 
returns to Westwood’s view, and even goes so far as to suggest 
that the specimens which were sent to him were probably the 
larvae of Lycus (Lycostomus) melanurus, Blanchard.' The opin- 
ions of other authors are similarly divided. 
Gahan (1913) favours Lycidae, but does not think the insects 
can belong to the genus Lycus,as they are very unlike the authenti- 
cated larvae of that genus. He thinks it more probable that they 
belong to some genus in which only the male—perhaps not even the 
male*—is winged. Further, he points out that the known distri- 
bution of ‘‘ Trilobite Larvae” corresponds to that of the genus 
Lyropaeus, of which only males are known to him ; and he suggests 
an association with this genus. His conclusion is in a measure 
confirmed by the above observations on the development of 
Lyropaeus biguttatus, and it is noteworthy that all the winged 
specimens that I have seen are males. 
The larvae which give rise to these winged insects are, 
however, not particularly large, and throw no certain light on the 
status of the much larger insects with which the name ‘‘ Trilobite 
Larvae’’ is more particularly associated. Two large insects of the 
‘“ Trilobite’ type were also, however, found in the Cochin forests. 
These are figured on pl. xx, figs. 9-12. 
One of them (pl. xx, figs. 9-10) is very like the larvae found 
to develop into males of Lyropaeus biguttatus. The principal 
differences are the presence of more definite tubercles at the 
angles of the thoracic terga in the former than in the latter; 
the paler colour of the upper surface; and the yellow colour of 
the legs and sterna and of the lower surface of the lateral ex- 
tensions of the terga, which contrast strongly with the black 
pleural structures. These, however, are features which may well 
be acquired only as maturity is approached. The specimen is 
not nearly so large as many species are known to become, and 
dissection has shown it to be immature; but it may perhaps 
represent a stage in the development of the female of Lyropaecus 
biguttatus, a female which in that case will almost certainly 
prove to be larviform. 
The other specimen of ‘‘ Trilobite Larva’’ found in Cochin 
(pl. xx, figs. 11-12) is slightly smaller, is black in colour, and is 
ornamented with more numerous and more elaborate tubercles and 
| Authenticated larvae of this species have since been briefly described by 
Shelford (Rep. Brit. Ass., 1901, p. 690). They do not appear to be of the 
‘“ Trilobite’ type, and are only 25 mm. long when full grown. 
2 See also Shelford’s comment on a previous note by Gahan (Joc. cit. 1908) 
