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THE SCULPIN AND ITS HABITS 



349 



but more or less swollen aboul 

 naked, but in some incompletely 

 bases which curve forward 

 and downward, and in one 

 form (Synchirus) are even 

 connected below, and the ven- 

 trals are imperfect, having' a 

 spine (closely joined to the 

 next ray) and two to four 

 (exceptionally five) simple 

 rays. 



The most distinctive charac- 

 ters, however, are furnished 

 by the skeleton and especially 

 by the shoulder girdle. The 

 two bones, hypercoracoid and 

 hypocoracoid, which in most 

 mail-cheeked fishes, as in 

 others, intervene between the 

 great shoulder bone and the 

 four bones at the base of the 

 pectoral fin, are in the Cottids 



the abdomen ; the skin of most is 

 scaled; the pectorals have expanded 



U>3 



fiX lit g> 



"7 



Fig. 46. — Shoulder girdle of the Sculpin 

 (after Parker), showing the intervention 

 of the second and third actinosts between 

 the first and fourth actinosts (b. 1 and 

 b. 4) and the hypercoracoid (sc) and hypo- 

 coracoid (cr). b. brachials or actinosts; 

 cl. clavicle ; cr. f. coracoid (hypocoracoid) 

 foramen; i. cl. interclavicle ; //. 2, 3, lateral 

 line scutes ; p. cl. postclavicle ; p. cr. pro- 

 duced coracoid (hypocoracoid) ; pt. post- 

 temporal ; sc. scapula (hypercoracoid) ; 

 sc. n. scapular notch ; st. supratemporal. 



so reduced and shoved out of place that the 

 middle at least of the basal bones (acti- 

 nosts) connect with the great shoulder 

 bone. 



Other important osteological characters 

 are coincident with these and manifest in 

 modifications of the vertebrae, relations of 

 the ribs, and structure of the skull. 



Most of the salt-w r ater Cottids (Myx- 

 ocephalines) have large branchial aper- 

 tures and narrow isthmus or none at all ; the skull also differs notably 

 from the fresh-water forms, the hinder portion being oblong and 



Fig. 



47. — Skull of Sculpin 

 (after Girard). 



