92 CRETACEOUS AND TERTIARY FISH. 



of median transverse sutures and those uniting median and lateral 

 teeth, as well as these together, remarkable for their unusually 

 serrulate condition. Root surface slopes strongly in each side 

 from median line. Vertical diameter of median tooth about one- 

 sixth of horizontal. Length (width) about 27 mm. (From 

 Leidy.) 



Leidy originally identified this species with Myiiobatis serratus 

 Meyer, though according to Hay, as the latter was from the 

 lower Miocene, he names Leidy's specimen M. leidyi. Leidy also 

 pointed out its resemblance to the dental armature of Myiiobatis 

 toliapicns Agassiz and M. suturalis Agassiz. 



Formation and locality. Known only from the above-described 

 dental plate ascribed to the [Manasquan, K.] marl of Pember- 

 ton in Burlington County (C. H. Budd). I have not located it 

 in the collection of the Academy, where it was originally de- 

 posited. 



Myliobatis rectidens Cope. 



Myiiobatis rectidens Cope, Proc. Amer. Philos. Soc. Phila., XI, 1870, p. 294. 

 Harrisonville, Gloucester Co., N. J. Miocene? 

 Hussakof, Bull. Amer. Mus. N. H., XXV, 1908, p. 32, fig. 9 (type). 



Dental plate apparently depressed in form, composed of seven 

 median teeth and at least two series of lateral teeth each side. 

 Median teeth entirely plane and with perfectly transverse sutures, 

 the series very slightly convex in both directions. Vertical diam- 

 eter of median teeth about five in horizontal diameter. Several of 

 lateral teeth in inner series at least wider than long. Length 

 (width) about 70 mm. (damaged). (Largely from Cope.) 



Cope says this species resembles Myiiobatis gigas Cope, though 

 in the latter there are twice as many, or 12, teeth in a series of the 

 same length and width as the present. In this species the median 

 series are straight and in Myiiobatis gigas 1 are recurved at the 

 extremities. 



Formation, and locality. The type specimen now in the Ameri- 

 can Museum of New York seems to be the only one known. Cope 



'Eastman identifies Myiiobatis vicomicanus Cope with this species in Md. 

 Geol. Surv. Miocene, 1904, p. 73, PI. 28, figs. 3a, 3b, PI. 29, figs, ia, ib. 



