1907.] OF THE SUBORDER ALLOTRIOGNATHI. 641 



bones not articulated to the coracoids. Fins composed of articu- 

 lated rays, except the first two rays of the dorsal, which are 

 spinovTS ; dorsal and anal fins long ; ventral fins of 8 or 9 rays. 



Family Yeliferid^. A single genus, Velifer Schleg. 



Division 3, TaBniosomi (Gill). 



Body elongate, strongly compressed ; skeleton feebly ossified, 

 the bones thin ; cranium with a considerable amount of cartilage. 

 An antei'ior cranial chamber or groove, the walls of which are 

 mainly formed by the frontals, the floor by cartilage containing 

 the mesethmoid and orbitosphenoid ossifications ; mesethmoid 

 entirely posterior to the prfefrontals ; epiotics meeting behind 

 the supraoccipital. Vertebrte numerous (90 to 93) ; prfecaudals 

 with downwardly directed parapophyses ; ribs feeble or absent, if 

 present attached to the parapophyses. Post-temporal simple ; 

 pectoral fin-rays inserted on the scapula and on 3 pterygials, two 

 or all of which are in contact with the coracoid ; pelvic bones not 

 articulated to the coracoid, but inserted in the ligamentous tissue 

 between them. Fins composed of flexible, non-articulated rays 

 (the first ray of the dorsal sometimes spinous) ; dorsal fin very 

 long ; anal short or absent ; ventral fins, if present, of 1 to 9 rays. 



Family 1. Trachypterid.e. 



Ventral fins present, close together, of 1 to 9 rays ; no anal fin ; 

 vent about in the middle of the length of the fish. 



Two genera, Trachypterus Gouan, and Regalecus Briinn. 



Family 2. Lophotid^. 



Ventral fins, if present, small, of 5 or 6 rays, widely separated, 

 inserted a little below and behind the pectoi-als ; a shoi't anal fin ; 

 vent posterior, just in front of the anal. 



Two genera, Lophotes Giorna, and Eumecichtliys Regan. 



3. Systematic Position of the AUotriognathi. 



The AUotriognathi and the Beryciformes are the only fishes 

 which combine the presence of an orbitosphenoid with the absence 

 of a mesocoracoid. The two groups agree also in having the 

 ventral fins placed more or less anteriorly and often composed of 

 a large numljer of rays (up to 17 in the AUotriognathi, up to 14 

 in the Beryciformes), and in being physoclistic (with the exception 

 of Beryx and Holocentnmn). 



In cranial structure the Beryciformes difier from Lampris (which 

 has the most generalised cranium of the AUotriognathi) only in 

 being less specialised ; i. e., the opisthotic is well-developed, the 

 maxillary carries 1 or 2 supramaxillaries, is normaUy articulated 

 to the vomer and is attached to a process of the palatine. The 

 pectoral arch of Velifer is identical with that of the Beryciformes. 



Taking the Beryciformes in the most restricted sense, they 



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