J06 



CI ran I) A 'I A. 



brane with secondary folds wliicli cxtcinl on anterior and posterior 

 sides of tlie cleft. Eaoli aj'cli excejit tlie last, as the sections (fig. 

 oO-t, A, and 595) show, l)ears two rows of gill folds (denii- 



Fi(, i'li— Phai'Mit'e', of U) El isni,,bi uk h iVmi<nHi) and (C TeleDSt (r,a Jhs), the 

 skuU iLmo^ed And on the ktt th( ^111^111^ cut across, d, attathnunt ot upiitr 

 jaw to cranium ; ax, outer gill slit; h, gill arch; ?.(', ;.;=, anterior and posterior 

 Kills ulemibranohs); /(, dermal projection; J/iii, hvomandibular ; is inner "ill 

 cleft; ;;i, mouth; ma, maxiUare ; a, oesophagus; op, operiMilum : op's, opercular 

 openmg ; pa, palatme; p/ii, inferior pharyngeal bones; /lo, ptervgoquadrate • 

 prill, premaxilla ; .•,-, shoulder girdle ; vk, h.wer jaw; 2, tongue. 



hranchs) which helong to different clefts and are separated from 

 each other by tissne containing the cartilaginous gill ravs. 



In the second type (/;), which occurs in all other fishes, the 

 dermal l)ridges are lacking, and the tissue Ix-tween the demi- 

 branchs has more or less completely disappeared, so that the 

 demibranchs ot <ine a.rcli become cdiineeted, their free ends pro- 

 jecting into the water like the teeth of a double comb. Here, 

 on account of tlieir veiy ibdicate structure, thev wmild be ex- 

 l)osed to serious injury were they not protected by the operculum 

 or gill cover. 'I'his is a (old of skin 'irising from the hyoid arch 

 and cxtcinling liark ovi'i' tbc gill region. It is supported by two 

 grou)is of Imiik's, Idle oiirrcuhif JMiiies |)r(_>per (tig. 58'.l, 0, ,So, lo, 

 J'ro), attacbed lo the byoniandiinikir, and the bramdiiosteo-als 



