DASYBATUS TORREI. 387 



distance behind the head. Eyes very small. Mouth small; cleft waved; lower 

 jaws prominent at and near the symphysis; upper jaws indented at the symphy- 

 sis, with a prominence farther out at each side. Teeth small, in quincunx as in 

 other Dasybati, larger on the prominences of the upper jaws. The inner edge 

 of the crown, that toward the throat, of each tooth is longer, a semicircle, and, 

 on the male, has a sharp point on the middle; the crown is rough and is crossed 

 by a transverse groove in front of a prominent rugose ridge and behind another 

 of less prominence and length. The sharp point on the hind edge of the tooth 

 is probably a feature of the males as they become mature. Spiracles large. 

 Scales on body and tail small, closely set, farther apart and decreasing in size to 

 minute near the edges of the disk and on the sides of the tail. On the middle of 

 the top of each scale there is an apex from which ridges, commonly four, radiate 

 dichotomizing distally. A group of several small tubercles, enlarged scales, 

 appears at each side of the vertebral column on the shoulder girdle, the groups 

 separated from one another by about two fifths of the distance between the 

 spiracles. No other tubercles on body or tail. Entire lower surfaces and tops 

 of ventral fins smooth. Tail about one and one half times as long as the disk, 

 strong anteriorly, becoming quite slender behind the serrated spine, or spines, 

 rounded on the top, as in D. marinus, that is, without a trace of a dermal fold, 

 with a low fin fold on the lower side, below the spine and about twice its length. 



Olivaceous brown, darker above the margins; tops of ventrals rusty brown. 



Length of body about 19 inches; length of tail 29; greatest width 2l\, at 

 l\ inches from end of snout; nostrils to end of snout 2|, their distance apart 

 about I2; vent to serrated spine \2\; distance between groups of tubercles on 

 the shoulder girdle l\; diameter of eye \ inches. 



Specimen described a young male from Tunas de Zaza, Cuba received from 

 Dr. Carlos de la Torre y Huerta. 



This sting-ray is placed between the typical Dasybati and the Potamotr^- 

 gones. It differs from the latter in lacking enlarged tubercles on the vertebral 

 line and in lack of a keel-like compression on the top of the tail. Its scales also 

 differ from those of P. hystrix and other Potamotrygones in that on those species 

 the ridges of the crowns do not dichotomize outward but the increase in the num- 

 bers of ridges is made by other ridges that rise independently between the 

 primary ridges. On the scales of Dasybatus torrei each ridge divides into two and 

 each of these again divides into two and so on. Most likely Lebisa is somewhat 

 allied to D. schmardae described by Werner from Jamaica. Both species are no 

 doubt without the cartilaginous prepelvic spine so characteristic of the river 



