414 THE PLAGIOSTOMIA. 



Snout to abdominal pores half the width of the disk. Tip of snout a shght 

 prominence. Anterior margin of pectoral waved, concave in the middle, outer 

 and hinder angles rounded somewhat broadly. No tentacle on the spiracle. 

 No dorsal fin. Tail less than half the length of the body, with a shght fold above, 

 behind the spine. 



Brown with black puncticulations; yellowish below. Rarely with white 



spots. 



Gulf of California. 



Pteroplatea micrura. 

 Plate 33, fig. 3-4. 



Raia micrura Schneider, 1801, Bloch Ichth., p. 360. 



Raia maclura Lesueur, 1817, Journ. Acad. nat. sci. Phil., 1, p. 41, fig. 



Trygon maclura Cuv., 1829, Reg. anim., 2, p. 400. 



Pteroplatea maclura Muller & Henle, 1841, Plagios., p. 169; Dumeril, 1865, Elasm., p. 614; Gunth., 



1870, Cat. fishes Brit, mus., 8, p. 487; Jord. & Everm., 1896, Bull. 47, U. S. nat. mus., p. 86. 

 Pastinaca maclura DeKay, 1842, N. Y. fish., p. 375, pi. 65, f . 213. 



Length of disk more than half the width. A low angle in front of the snout. 

 A shght indentation in front of the middle of each pectoral; outer ends of 

 pectorals subangular, hind margins and angles broadly rounded. Length of 

 snout from the eyes of a specimen sixteen inches wide equals the distance be- 

 tween the spiracles. The caudal spines appear later on individuals of this 

 species, which is one reaching a great size. 



No tentacle behind the spiracle. Tail slender, tapering, with a distinct 

 fold above and a weaker one below, entire length little more than one fourth of 

 the length of the body from the snout to the pores. 



Ohvaceous or brownish puncticulate and vermiculate with lighter; tail 

 dark with four or five bands or blotches of hghter. 



The only items of importance in Bloch's description of Raia micrura con- 

 cern the tail, "nigro alboque fasciata," and the locality, "Habitat in Surinamo." 

 These would fix the name micrura upon the West Indian species, later described 

 by Lesueur as R. maclura, rather than on the East Indian form figured by 

 Russell and named by Shaw Raia poecilura. 



Pteroplatea marmorata. 



Pteroplatea marmorata Cooper, 1863, Proc. Cal. acad. sci., 3, p. 112; Jordan & Gilbert, 1882, Bull. 

 16, U. S. nat. mus., p. 47; Garman, 1888, Bull. M. C Z., 17, p. 101, pi. 43, f. 2; Jord & Everm., 

 1896, Bull. 47, U. S. nat. mus., p. 87. 



Disk less than twice as wide as long. Anterior margin of pectoral waved 

 in young, slightly concave in the middle, nearly straight and snout longer and 



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