724 CONTEIBUTIONS TO NOKTH AMERICAN ICHTHYOLOGY IV. 
the isthmus; ventral fins thoracic, dose together, imperfect, I, 2 or I, 3; 
spinous dorsal small, sometimes absent; anal short, similar to soft dor- 
sal, without spines; caudal narrow, few-rayed; pectorals entire, with 
broad base, the rays mostly simide; pyloric coeca few; air-bladder 
none. Small fishes, chiefly of the Arctic Seas. Genera about 10; spe- 
cies about IG. They feed chiefly on Crustacea, and are often found at 
considerable depths. 
(Triglidce, group Cataphracti pt. Guntlier, ii, 211-216.) 
a. Spinous dorsal obsolete ; gill-uiembranes free from the isthmus. (Aspidophoroidince.) 
Aspidopiioroides, 381. 
aa. Spinous dorsal present. 
b. Gill-membranes free from the isthmus; lower jaw projecting, 
c. Body extremely elongate; snout forming a tube; chin with a single long 
barbel Siphagoxus, 382. 
cc. Body fusiform, less elongate; snout not forming a tube; chin without barbel. 
Brachyopsis, 383. 
bb. Gill-membranes united to the isthmus, lower jaw included. 
d. Bony plates of body without spines. 
e. Vomerine teeth none; no occipital pit Agonus, 384. 
ee. Vomerine teeth present ; a deep pit at the occiput Bothragohus, 385. 
dd. Bony plates of bodj^ ending in spines. 
/. Vomerine teeth present Odonto pyxis, 386. 
ff. Vomerine teeth none Podothecus, 387. 
3§1.— ASPIDOPIIOROIDES Lac^pMe, 
{Anoplagonns Gill.) 
(Lac<^p^de, Hist. Nat. Poiss. iii, 223, 1802: type Aspidopiioroides tranquebar Lac. = Cottus 
monopterijgius Bloch. ) 
Body very long and slender, subterete, octangular, tapering into a 
very long six-sided tail. Head slender, short, with large eye; mouth 
small, terminal ; jaws and vomer with villiform teeth. Dorsal fin 
single, without spines, very small, inserted nearly opposite the still 
smaller anal; other fins small; bony plates of body keeled, without 
spines; gill-membranes broadly united, free from the isthmus. (aV-)?, 
shield; (’’opiu)^ to bear; appearance.) 
a. Nasal spines very strong. 
1109. A. monopteryg'iiis (Bloch) Storer. 
Brownish, obscurelj’ banded with darker; pectorals, dorsal, and cau- 
dal mottled or barred. Head triangular, much narrowed anteriorly; 
nasal spines very large, diverging, inserted near tip of snout; no other 
spines anywhere; eyes very large, longer than snout; supraocular 
ridges very high; a ridge extending backward from eye along tern* 
