1925 ] Second Abdominal Pleurite in Higher Coleoptera 291 
chitinized, except on the mid-ventral line where the second 
segment takes the form of a strong keel, filling the space between 
the coxse. The second pleurite is frequently completely mem- 
branous, but in the species figured (Trypopitys) it still shows 
some feeble chitinization and even a few rudimentary hairs 
Fig. 1. 
Each figure gives a ventrolateral view of the junction of thorax and 
abdomen, with the articulation separated to expose the membranous struc- 
tures. The variously shaded areas represent sclerites, the plain white, mem- 
brane. Hairy surfaces indicated, pads for the reception of the elytra stippled, 
the plain chitin striated. 
Ai Membranous first sternal region of abdomen. A 2 Membranous 
second sternal region of abdomen. eps 3 Metepisternum (the hairy ventral 
portion only is exposed when the elytra are closed). epm 3 Metepimeron 
(apex uncovered in Trypopitys, wholly covered in Hemicrepidius). pl 2 , pl 3 , 
pl 4 Pleurites of successive segments of abdomen, ph rudimentary chitinous 
nodule, perhaps representing the first pleurite. st T 3 Metasternum of thorax. 
st A2 , stAs, stA 4 Successive sterna of abodmen. art. Articular facets in- 
dicating the junction of metepimeron and second (or third) pleurite. WP Wing 
process. Heavy solid line. Edge of superficial portion of pleura, adjoining 
pleura of thorax in life. Heavy broken line. Edge of coxal cavity on surface 
of third sternite. 
Fig. I, A. Bostrychiformia, Anobiidae. Trypopitys sericeus. 
Fig. 2 ,B. Serricornia, Elateridse. Hemicrepidius species. 
