Jordan and Evcrmann. — Fishes of North America. 1243 



h-h.. Top of head naked ; an oblique band of scales on each 

 aide of nape; parietal crest not confluent with the 

 fronto-occipital crest, either fading away ante- 

 riorly or running into the ocular rim; preopercle 

 with a shallow notch or eiuargination only. 



Nkoivlenis, 525. 

 gg. Fronto-occipital crest continued forward along top of head 

 to nearly opposite nostrils ; prefrontals with the pos- 

 terior area short, excavated above and in front. 

 i. Gill rakers short and few, about 12; anal fin long and 

 low, its rays III, 10 or 11. Rabieubia, 526. 



ii. Gill rakers long and numerous, about 25 ; anal rather 

 high, its rays III, 9; pterygoid teeth present (in 

 the adult) in a narrow band ; caudal fin very deeply 

 forked. OCYURUS, 527. 



//. Prefrontals with the articular facets developed from simple 

 tubercles and not V-shaped; basisphenoid not lobigerous; 

 canines small; soft rays of dorsal 10 or 11. 

 j. Prefrontals with the posterior areas cribriform ; pterygoids 

 with a broad patch of teeth (in adult) ; hyoid bones and 

 tongue with teeth; canines very small or obsolete; dorsal 

 spines 12 (or 13); soft dorsal and anal somewhat scaled; 

 top of head scaled to before middli- of eye ; gill rakera 

 numerous. Rhomboplites, 528. 



yj. Prefrontals with the posterior areas solid and somewhat 

 tumid ; pterygoids, hyoid bone, and tongue toothless ; dor- 

 sal spines 10 ; soft dorsal and anal scaleless . 



Apsilus, 529. 

 Etelin^ : 

 ee. Interorbital area flat, separated by a transverse line of demarcation 

 from the occipital, by which the median as well as the lateral 

 crests are limited; frontals wide in front; tongue and pterygoids 

 toothless ; soft rays of dorsal 10 or 11. 

 k. Dorsal fln continuous; frontals not cavernous; supraorbital 

 margin crenate; periotic region much swollen outward and 

 with the bones thin and polished; preorbital moderate; 

 frontals behind with funnel-shaped foraminae ; soft dorsal 

 and anal scaleless; last rays of dorsal and anal produced. 



Apeion, 530. 

 Ick. Dorsal nearly or quite divided into two fins by a deep notch ; 

 eyes very large ; preorbital very narrow. 



I. Frontals not cavernous, simply normally perforate ; supra- 



orbital margins crenate ; periotic region little convex 

 and with the bones thick, unpolished; prefrontals 

 behind with funnel-shaped foramina; body compara- 

 tively elongate ; head naked above and on snout; soft 

 dorsal and anal naked ; peritoneum and lining of gill 

 cavity pale; caudal deeply forked ; color crimson. 



Etelis, 531. 



II. Frontals cavernous (like those of iScicenoids), with longi- 



tudinal, osseous bars, leaving interspaces in front of 

 transverse ridge and on each side near the front; 

 supraorbital margins smooth ; prefrontals behind with 

 simple foramina for olfactory nerves ; body compara- 

 tively short and deep; head scaly above and on jaws 

 and snout; soft dorsal and anal scaly at base; peri- 

 toneum and lining of gill cavity black ; caudal lunate. 

 Deep-water species, blackish-purple in color. 



Vebilus, 532. 



