FISHES—REGAN. 11 
CHAENICHTHYIDAE. 
The “Terra Nova” collection includes examples of two species of a new genus of 
this family, and also new species of Chionodraco and Cryodraco, genera new to the 
British Museum collection. The synopsis of the genera given in the “ Scotia” report 
may be modified as follows :— 
I. Middle rays of pelvic fin longest ; two lateral lines. 
A. Lateral line without bony plates. 
D. rx-x, 33-40, A. 32-38. no rostral spine ; : ; : Champsocephalus. 
D. xm-xv, 28-31. A. 25-27. a rostral spine : : 5 ; 6 Pagetopsis. 
B. Lateral line with bony plates ; a rostral spine : : : : 5 .  Chaenichthys. 
II. Two outer soft rays of pelvic fin longest. 
A. Sub- and inter- operculum not spinate ; rostral spine reduced or absent. 
Pelvic fins comparatively short, with the rays branched or bifid ; spinous dorsal large, of 
seven or eight spines, separated by a short interspace from soft dorsal; two lateral 
. Chaenocephalus. 
lines 6 2 5 7 : : : : 
Pelvic fins long, with the rays simple ; spinous dorsal reduced, of three to five spines, 
separated by a long interspace from soft dorsal ; three lateral lines : Cryodraco. 
B. Sub- and inter- operculum bearing a pair of spines behind angle of praeoperculum ; rostral spine 
well developed ; three lateral lines. 
Pelvies 1 5; gill-rakers reduced to a few vestiges near the angles of the arches ( ‘hionodraco. 
Pelvics 14; gill-rakers developed as dentigerous knobs or patches . . Chaenodraco. 
20. Pagetopsis macropterus, Bouleng. 
Three examples from McMurdo Sound, 100 to 200 fathoms. 
21. Cryodraco atkinsoni, Regan (Pl. v1, fig. 2). 
Cryodraco atkinsoni, Regan, Ann. Mag. Nat. Hist. (8), x11, 1914, p. 13. 
rc 
Depth of body 73 in the length, length of head 33. Diameter of eye 5 in length 
of head, interorbital width 42. Snout 1 the length of head. Maxillary nearly reaching 
middle of eye. Rostral spine and. symphysial tubercle of mandibles vestigial. Dorsal 
1H, 42 ; spinous dorsal above base of pectoral, its spines connected by membrane, the 
first and second subequal, 4 the length of head. Anal 46; origin a little in advance of 
that of dorsal, nearer to end of snout than to base of caudal. Pectoral nearly 3 length 
of head, extending to seventh ray of anal ; pelvies 14 as long as head, extending to 
middle of dorsal fin. Caudal slightly emareinate. Dark spots on head and cross-bars 
on body ; spinous dorsal blackish ; pelvics dusky. 
A single specimen, 292 mm. in total length, from the Ross Sea, 74° 25’ S., 179° 3’ E., 
158 fathoms. 
This species is named after Surg. E. L. Atkinson, R.N. ; it differs from C. antareticus, 
Dollo, in the smaller eye, shorter pelvic fins, ete. C. pappenheimi, Regan, has the 
pelvic fins still shorter, and in its large head and 5-rayed dorsal fin seems to approach 
Chaenocephalus. 
Cc 2 
