SHARKS AND RAYS OF BEAUFORT, NORTH CAROLINA. 



279 



Family RHINOPTERlDyE. The cow-nosed rays. 

 Genus RHINOPTERA Kuhl. 



35. Rhinoptera quadriloba (Le Sueur). Cow-nosed ray; devilfish. 



Rhiiioplera quadriloba, Wilson, 1900. p. 355. 



Rhinoptera bonasus. Smith, 1907, p. 47: Gudjter, 1912, p. 152: Coles. 1914, p. 94. 



Teeik. — Teeth in a male 84.8 cm. long in 9 rows in the upper jaw and 8 in the lower, in pavement, 

 median row in upper jaw widest, 2.6 in width of dental plate, second row on right side of wider teeth 

 than the others, 2.5 in width of median row; with the exception of the marginal row on each side the 

 other teeth are hexagonal; median row of lower teeth widest, four-fifths as wide as median row in upper 

 jaw, each succeeding row smaller; 12 teeth in a row in upper jaw, 5 functioning; 13 in lower jaw, 6 

 functioning; functioning teeth deeply pitted. In this species the dental plates are more nearly 

 subequal than in either of the preceding. Skin smooth, a narrow serrated spine immediately behind 

 the dorsal fin. 



Measitrements of a Female (No. i) 6o.i Cm. (23H Inches) Long and a Male (No. 2) 84.8 Cm. 



(33^ Inches) Long. 



Length of disk 



Breadth of disk 



Length of anterior margin of disk 



Length of posterior margin of disk 



Snout 



Horizontal diameter of eye 



Interocular width 



Preoral length of snout 



Breadth of mouth 



Tip of snout to vent 



Tip of snout to inner angle of first gill slit. 

 Tip of snout to inner angle of fifth gill slit 



Interspace of anterior gill slits 



Interspace of posterior gill slits 



Length of ventrals 



Length of spine 



No. I. 



No. 



The stomach contained several small mollusks. This species is not uncommon in this region, 

 apparently being a resident here. More examples of it are brought into the laboratory than any of the 

 allied forms. 



Family MOBULID/E. The sea devils. 



KEY TO THE GENERA. 



a. Teeth on both jaws; mouth inferior Mohula. 



aa. Teeth on lower jaw only; mouth anterior Manta. 



Genus MOBULA Rafinesque. 



36. Mobula hypostoma (Bancroft). Small devilfish. 



Mobula olfersi, Coles, 1910. p. 341; Pellegrin. 1912, p. 414 (with photographs); Gudger. 1913a. p. 5; Coles, 1913. p. 33; id., 1914, 



p. 94. 



Mobula hypostoma, Gannan, 1913, p. 453, pi. 38, 54, 57, 59. 75. 



Teeth. — Teeth (male) in j- rows, minute; dental plate very long and narrow; teeth close-set, over- 

 lapping; posterior margin with one to five dentate prongs and with a minute cusp on the outer edge of 

 each she alder, a single row on upper jaw and several in the lower jaw about twice as wide as adjacent 

 rows; teeth in lower jaw relatively wider and with shorter cusps than those in the upper. 



Teeth in a female 142 cm. (56 inches) long in ^ rows, in pavement, arranged in quincimx, not nearly 



so close-set as in the male, not overlapping, rows of wider teeth present as in the male; posterior margins 

 of teeth smooth, or with slight ridges, apparently rudiments of the prongs characteristic of the teeth of 

 the male. Skin smooth, no caudal spine. 



