Chilton. — Ceina, nn Aherrant Genus of the TaUtridae. 



125 



is large and well developed, somewhat triangular in shape, strongly curved, 

 and slightly twisted so that its outer or lower surface is convex. It is 

 comparatively free from setae, but its surface shows numerous rows of 

 very minute striations, possibly caused by rows of very minute setules. 



I have not noticed any differences between the mouth-parts of male 

 and female specimens such as occur in Hyale camptonyx (Heller), H. grenfelli 

 Chilton, and possibly in some other species. The differences between the 

 male and the female appear to be confined to the second gnathopoda. 



The first gnathopod of the male (fig. 14) is of normal shape, its side 

 plate rectangular with the longer angles rounded, the carpus slightly 

 shorter than the propod, triangular, its hind-margin fringed with stout 





Fig. 13. — Ceina egregia ; maxilliiie(is. 



Fig. 14. — Ceina egregia ; first gnatliopod of male. 



Fig. 15. — Ceina egregia ; second gnathopod of male. 



setae ; the propod oval, palm rather oblique, straight or slightly curved, 

 defined- by a stout spinule with subapical cilium. The palm is fringed 

 with a row of simple setae, and the hind-margin and surface of the joint 

 near the hind-margin bear numerous fairly stout setae, all serrate or 

 pectinate. 



The second gnathopod in the male (fig. 15) is very large and very 

 different from that of any of the species of Hyale known to me. The side 

 plate is rectangular, rather deej)er than broad, with margins entire and 

 free from setae ; the branchia is long and narrow. The basis is long and 

 slender, broadening only slightly distally ; its anterior margin is grooved 

 and produced into a small lobe at the distal end ; the ischium is short, 

 with the anterior outer margin produced into a rounded lobe ; the merus 



