igo MciHoirs of the Indian Mu^cnm. [\'ol.. Ill, 



to which the abdominal segments have telescoped and sunk in beneath the ends of 

 the elytra. Even the puncturing is variable as a rule. It occurs with distinct- 

 ness chiefly in the Leptaulacinae and in one or two genera of Aulacocyclinae. In the 

 former subfamily two types of puncturing can be recognized. One, which occurs in 

 a single species only (Leptaulacides planus t and is the principal character by which 

 that species can be recognized, is a uniform, close, shallow and moJerately fine punc- 

 turing which occurs over the whole lower surface of the abdomen. The other, 

 which occurs to some extent in other subfamilies also, is a close, but finer and 

 stronger punctur.'ng, centred in the scars, beyond which it extends to an extent 

 which is apt to be extremely variable even within the limits of a single species; this 

 at best affords evidence for the separation of species into somewhat vaguely character- 

 ized varieties. The puncturing found on the abdominal sterna of certain Aulacocycli- 

 nae (eg species of the genus Comampes) is of yet a third kind, being coarse 

 and sparse, with a hair (of which all trace may have disappeared in a worn specimen) 

 rising in fresh specimens out of each puncture. The presence or absence of this type 

 of puncturing appears to be a useful confirmatory generic character, and its extent, 

 when present, a confirmatory specific one. 



Legs. 



The coxae, or basal joints, of the first pair of legs present one of the chief charac- 

 ters by which species belonging to the subfamily Aulacocyclinae can be distinguished 

 from those belonging to the subfamihes of the second section of the family ; for 

 although they are always transverse and embedded in the prothorax over the greater 

 part of their length, they project downwards distally to a greater extent in the 

 Aulacocychnae than in the other subfamilies (compare text-figures i F and i G). No 

 other joint of the first leg has proved to have any taxonomic value in any of the 

 species I have seen, except the tibiae which are occasionalh- important, at least in 

 the genus Taeniocenis. 



The coxa of the second leg is very small and need not be considered here, but 

 that of the third leg resembles that of the first in size. Its exposed face is divided 

 longitudinally into a raised anterior and depressed posterior part ; and the presence 

 or absence of punctures on the latter affords a useful confirmatory specific character. 



Neither the small trochanters nor the longer femora of the second and third legs 

 are of any taxonomic importance; but in the Aulacocychnae there is often, about 

 two-thirds of the way down the outer side of the tibia of each of these legs, a small 

 spine, the presence or absence of which can frequently be utilized in checking a specific 

 identification. Of these spines, those on the hind tibiae are the more useful, as the 

 extent to which they are developed differs more in different species. 



Elytra . 



The elytra of all Oriental Passalids are marked each with ten grooves, with ribs 



between them. On the dorsal surface the ribs are always flat, and much broader than 



the grooves, but laterally the grooves may be as broad as, or broader than, the ribs. 



Each groove contains, as a rule, a row of more or less distinct punctures, which are 



