30 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



some of which are sometimes irregularly crowded tojiethcr. Between the dorsals there are, 

 as a rule, few spines. The teeth form from forty-oue to forty-four series iu the upper, aud 

 from forty-one to forty -three iu the lower jaw. Coloration dark grayish brown above; the 

 mucous pores marked with black vermicular spots. Lower surface blackish, without spots. 

 [Garman and Giinthcr.) 



This species is locally not uncommon on the Norwegian coast; for instance iu Thi'oudh jem 

 Fjord, at a depth of MO to 200 fathoms. It is one of the larger skates, the specimens iu the 

 British Museum measuring from 38 to -16 inches in width. 



Order HOLOCEPHALI. 



HolocephaJa, Mi'LLER, Abhaudl. Akad. Wiss. Berlin. 1834, 74.— GOntheh, Cat. Fish, lirit. Mus., viii, :ils. 

 Holocephali, Gill, MS. 



Selachians distinguished by the confluence of the hyomandibular bone with the cranium, 

 the coalescence of the ma.Killary and palatine elements with the skull, the development of 

 a rudimentary operculum, and the existence of a single external gill opening on each side 

 behind the head, ((iill.) 



Family CHIM>ERID>E. 



ChimaHdas, GC'NTHER, Cat. Fish. Brit. Mus., viir, 1870, 349. 



Body rather robust, elongate, tapering posteriorly. Head comju-essed. MoutJi inferior. 

 Upper lip deeply notched. Nostrils confluent with the moutli, separated by a narrow- 

 isthmus. Jaws with the teeth confluent into four bony lamiuje above and two below. No 

 spiracles. Males usually with a cartilaginous hook on the ujiper ])ait of the snout, armed 

 with prickles at the tip, and turned forward. Pectoral fins free, placed low. Ventral (ins 

 abdominal, many-rayed, provided in the male with claspers. Dorsal fin usually divided, 

 anteriorly with a very strong spine, which is grooved beliind. (Caudal fin low, fold like. 

 Skin naked, rarely somewhat prickly. Lateral line present, usually with numerous branches 

 anteriorly. Three free gills and two half gills. 



KEY TO THE GENERA OF CHIMiERID^. 



I. Male with cephalic appendage. 



A. Snout soft, not terminating in a cutaneous flap; tail not bent forward. 



1. Posterior appendages tripartite CniM.KU.v 



2. Posterior appendages bi|)artite HYDKOLAtiCS 



B. Snout tenuinatiug in a cutaneous flap CALLOHHYiNXiius 



II. Male without cephalic .ippendage ; .snout very elongate Harriotta 



CHIM^^RA, Llnnseus. 

 Chimara, Linn.eus, Mus. Ad. Frid., i, 53; Syst. Nat., ed. x, 1758, i, 2,S6. 



Holocephali with head somewhat compressed, snout without appendage. Eyes lateral, 

 very large. Lateral line forking anteriorly, forming several series of mucous tulies on the 

 head. Male with a club-shaped, cartilaginous hook above snout, curved forward and down- 

 w^ard armed ^vith decurved spines at tip, and fitting into a depression in front of eyes. 

 Ventrals rather large, with large bifld or trifld claspers in the male. Male with also rough 

 appendages at the base of the ventrals, protruding from a sheath of skin. First dorsal 

 triangular, preceded by a strong serrated spine which is grooved behind. Second dorsal 

 and caudal low, often notched. Tail sometimes produced in a filament. Skin smooth. 



KEY TO THE SPECIES. 



I. Pector.ils long, extending to tips of ventrals C. moNstrosa 



II. Pectorals short, terminating far iu advance of the veutrals C. .\KFINIS 



