56 ECHINOPERMA OF THE INDIAN MuSETTM. PART VIT. 



d' some or all of the distal division series 4 (3-(-4); no division series 2 

 (14-^) ; proximal pinnules stouter than the succeeding ; no combs on the 

 distal pinnules, 

 e' III Br series all 2. 



COMANTHERIA, p. 89. 



e^ TUB series 2 externally, 4 (3-|-4) internally. 



COMANTHINA, p. 91. 



e' IIIBr series 4 (3+4). 



COMANTHUS, p. 89. 



9. — Key to the Genera of ZYOOMETRin.E. 



a' Five arms only. 



EUDIOCRINU.S, p. 99. 



a* ten oi- more arms. 



h' ciiri short and stout, witliout dorsal spines or tubercles, and composed of 



less than 25 segments. 



catoptometra , p. 106. 



b* cirri long and more slender, with at least 20. and usually more than 30, 

 segments, of which the distal bear sharp dorsal spines. 



zygometra. p. 103. 



10.— Key to the Cenera of Himeroafetrid.^. 



a' Pp larger and longer than P, , wliicli in turn is larger and longei- than P, ; more 



than 30 arms. 



himerometra, p. 114. 



a* Pc smaller and weaker than P,, which, again, is smaller and weaker than P^. 



b' cirri tapering to a point distally ; distal cirrus sowments twice as long as 



broad • no dorsal spines nor carination. and no opposing spine ; terminal claw 



long and nearly straight; more than ten arms. 



craspedometra. p. 117. 



b* cirri uniform, not tapering distally; distal segments not so long as broad, 

 carinate, tubercular, or spinous dorsally ; opposing spine present; terminal 

 claw short, more or less strongly curved. 



c' middle and distal brachials exceedingly short and discoidal : IBr ossicles 

 and lower brachials swollen ; ten or more arms. 



AMPUTMETRA, p. 107. 



c* middle and distal brachials not especially short, more or less obliquely 

 wedge-shaped; ossicles of the IBr series and lower brachials not swollen; 

 more than ten arms. 



HBTBROMETEA, p. 120. 



