XTTT 



PHYLUM CHORDATA 



183 



mental characteristics with the Elasmobranchii, and is sometimes 

 included in that sub-class. Of the recent genera, Chimaara, the 

 so-called " King of the Herrings " (Fig. 858, A), is found on the 

 coasts of Europe, Japan, and Australia, the west coast of North 

 America, and at the Cape of Good Hope ; Callorhynchus (B) is 

 tolerably abundant in the South Temperate seas ; Harriotta is 

 a deep-sea form. 



External Characters. The general form of the body is 

 Shark-like, but the large, compressed head and small mouth are 



frcL 





FIG. 858. A, Chimaera monstrosa ; B, Callorhynchus antarcticus. a. cl. anterior 

 clasper ; a. cl.' pouch for its reception ; br. ap. branchial aperture ; c.f. caudal fin ; c.f.' its 

 whip-like prolongation ; d. /. 1, d.f. 2, dorsal fins ;fr. cl. frontal clasper ; I. /., /. /.' labial 

 folds ; 1. I. lateral line ; na. ap. nasal aperture ; op. operculum ; pet. /. pectoral fin ; ptg. 

 pterygopodia ; pv.f. pelvic fin ; t. teeth ; tc. tactile tlap ; ii.f. ventral fin. (A after Cuvier.) 



strikingly different from the depressed, shovel-shaped head and 

 wide mouth of most Selachians. The mouth is bounded by lip-like 

 folds, two. of which (B, l.f., l.f.'), placed laterally and supported by 

 labial cartilages, resemble the folds in which the premaxillae and 

 maxillae of many Bony Fishes are enclosed : a third fold, external 

 to and concentric with the mandible, is also supported by labial 

 cartilages and has the appearance of a second or external lower jaw. 

 In Chimera the snout is blunt, in Harriotta long and pointed ; in 

 Callorhynchus it is produced into a rostrum, from the end of which 



