No. 488] 



DIVING BEETLES 



in the thin lateral margins of the tarsus; the recurvatun^ 

 tarsi to a more dorsal position, in with the itiotion ot the 

 of gravity of the body t; and finallv th(> loss ot (he hind chi 



The modifications having to do with the takiiiu' and 

 of air are mn. h le.> ohxu.u. ...n^i.t in th. Ipi^ 



of the malum. ot tht (Kti.. ..h..idN mdiiionMlto, th.ii <oin, 

 and strenudu.un^ tun. t.om whi.h tnui to inak. ., ^^^u 

 air-compartiiicnt : and in the sh:i-hi luo.hlication ot the ii 



in the enlaruTincnt ot the hnnhno'-i ahdoininal -piraclc- to 



atus of terrestrial beedes has been cvidcntlv tairlv a(l«'(|uat 

 the main problem has been that ot i;(-ttiiiu' through tiic \\at( 

 sufficient ease and speed to capture picv and to t-^capc t 



The Larvae Studied.— Five sptH-ics ot hirvir ot DvtiM- 

 kept under observation. Unfortunatclv but one ot thtv-c 

 porus undulatus Say) was reared to the a.hih l»fctlr. 1 he 

 are here named tentativelv. it Ix-mu' possible to make a suppv 

 as to the genera to whicii thi^v belong:-, ba>ed on tl 

 of the Gvm pond, on their size, and on then' nk 

 Emopean form. The kn...t k.na Mnonnnnd 

 ^^ele tho.e of Ihn.di. Th, .e an ot iIh .muou^ 



book. We found them in Mav in -real number., fee.h 

 Corethra piipie in the deep narrow straits ol open water 1>« 

 standing aquatics, but thev are >o well known and the\- r 

 such quantities of live food (hulv, that we.hd not aiienipi t 

 them. Of still more snakv form aii.l with an e.piahv -o.hI 

 opment of s^\lnllmlu tiuu. . on h and the .i.lc ot n 

 abdominal sciiinents is the ai^ile hir\ a ot Aeihii.. Ir i> an e 



