XXIII ACANTHOPTERYGII 697 
Four genera, each with a single species: Anoplopoma (Scom- 
brocottus), from the North Pacific from Unalaska to California : 
Triglopsis, from deep water in Lakes Michigan and Ontario; 
Cottocomephorus, from Lake Baikal, and Comephorus from the 
greatest depths of that lake. As in many bathybial forms, 
Comephorus is colourless and provided with very large eyes; 
ventral fins are absent and the skeleton is very thin and papery. 
As a result of this condition, the second suborbital is not produced 
over the cheek, a unique exception to the main characteristic of 
this division; but no doubt can be entertained as to the propriety 
of referring it to the neighbourhood of Anoplopoma, since the 
recently discovered Cottocomephorus may be regarded as a con- 
necting link between the two genera. Comephorus is viviparous, 
and dies after parturition. Jordan regards 7'riglopsis as a relic 
of a former Arctic marine fauna. 
Fam. 4. Rhamphocottidae.—Head incompletely cuirassed, 
with spines; basis cranii simple; two nostrils on each side. 
Gill-opening narrow, above the base of the pectoral; gills 34. 
Vertebrae 24. Post-temporal short and flat, ankylosed to the 
skull; scapula and coracoid well developed, separated by cartilage; 
pectoral rays inserted on the scapula and on 4 plate-like pterygials, 
2 of which are in contact with the coracoid. Ventral fins close 
together, behind the pectorals, with a rudimentary spine and 3 
soft rays. Spinous dorsal shorter than the soft; no anal spines. 
Body densely covered with small prickly scales. 
Rhamphocottus richardsonii, a small fish 5 inches in- length, 
from the north-west coast of North America, is the only repre- 
sentative of this family. 
Fam. 5. Cottidae.—Head not or but incompletely cuirassed, 
usually with spines; basis cranii simple; parietal bones often 
meeting on the median line; two nostrils on each side. Gill- 
membranes free or attached to isthmus; gills 35 or 4; pseudo- 
branchiae usually present. Vertebrae 24 to 50, the anterior 
praecaudals with sessile ribs, the posterior with transverse 
processes, often directed downwards, or forming haemal arches, 
bearing ribs and epipleurals. Post-temporal more or less dis- 
tinctly forked; scapula and coracoid separated from each other 
1 Cf. Dybowsky, Verh. zool.-bot. Ges. Wien, xxiii. 1873, p. 475, and Zool. 
Centralbl. viii. 1901, p. 475; Zograf, Tagebl. zool. Congr. Berlin, No. 8 (1901), 
ids Be 
