Jordan and Evermann. Fishes of North America. 1911 



717. ICELUS, Kroyer. 



Icelus, KEOYER, Naturalist Tidsskr. i, 253, 1845 (hamatus). 



Head large. Preopercular spines 4, the upper hooked, simple or bifur- 

 cate at tip, without antler-like processes. Occiput with or without spines. 

 Body slender, fusiform, with a dorsal series of bony plates from neck to 

 base of caudal; lateral line with osseus tubercles; scattered scales on 

 Hides and belly. Gill membranes broadly united, free from the isthmus, 

 no slit behind fourth gill. Dorsals separate; ventrals I, 3, thoracic; no 

 pectoral filaments. Villiform teeth on jaws, vonier, and palatines. 

 Branchiostegals 6. Arctic regions. ("JxA.of, IcelitSj son of Hypnus, the 

 god of sleep; Kroyer says: "Navnet valgt med Hensyn till ulkearternes 

 Dorskhed, saavelsom til den Nordlige Bopael, nogle af Oldtidens Forfat- 

 tere anviste S0vnguden.") 



a. Anal rays 14 or 15; depth about 5 in length: dorsal IX, 18 to 20; occiput with 2 

 pairs of spines on each side, a deep median pit between them. BICORNIS, 2291. 

 nti. Anal rays 17 to 19; dorsal VII to IX, 19 to 24; depth 5 to 6 in length. 



b. Dorsal with 19 or 20 soft rays ; depth 5 in length ; occiput nearly plain, without 

 pit or prominent ridges. SPINIGER, 2292. 



bb. Dorsal with 23 or 24 soft rays. 



c. Dorsal spines IX; head wit li the mucous channels not greatly developed ; 



top of head scaly or prickly. 



d. Eye 2 to 2 in head, twice length of snout. EURYOPS, 2293. 



dd. Eye 2jj to 3 in head, 1 times length of snout; top of head with 3 

 pairs of filaments. VICINALIS, 2294. 



cc. Dorsal spines VII or VIII ; top of head mostly smooth ; opercles smooth ; 

 1 pair of filaments on top of head ; muciferous channels of head 

 highly developed. CANALICULATUS, 2295. 



aaa. Anal and dorsal rays unknown; body very slender; depth 7 in length; no occipi- 

 tal spines; eye 3 in head. AUSTEALIS, 2296. 



2-291. ICELUS BICORMS (Keinhardt). 



Head 3 ; depth 5. D. IX, 19 or 20 ; A. 14 or 15 ; V. 1, 3 ; P. 18 or 19. Head 

 large, naked ; upper preopercular spine small, hooked upward, bifur- 

 cate, !> spines below it, 2 of them hooked upward; 2 blunt occipital 

 spines; vertex depressed. Skin of body above with warty scales and 

 small prickles; some rows of bony scales from neck to base of caudal; a 

 scries of plates along lateral line; sides of body with scattered scales; 

 scales on sides between the plates variable, as also the scales below pec- 

 torals; small scales sometimes along base of anal; interocular space very 

 narrow, its width 4 in eye ; dorsals separated ; pectorals shorter than head ; 

 nuchal spines varying with age ; with the young the anterior pair half- 

 way between eye and posterior pair, with adults, the 2 pairs touching, 

 the posterior much longer ; preopercular spine simply emarginate in young ; 

 adult with the plates more rough ; no air bladder ; gill membranes broadly 

 joined, free from isthmus; no slit behind last gill. Yellowish, with many 

 brown spots. 



Ensign H. G. Dresel thus describes a fine example, 6 inches long, of 

 this species (No. 28630 U. S. Nat. Mus. collection) obtained in Davis Straits 

 by Mr. N. P. Scudder: D. IX, 20; A. 16; P. 18; V. 1,3; lateral line 41. 



