ELASMOBRANCHII. 95 



This seems to be the most abundant species found in New Jer- 

 sey, and is characterized largely by its convex surface, with 

 slightly convex striae posteriorly. 



Myliobates rugosus Leidy is preoccupied by Myiiobatis {Zygo- 

 batis) rugosus Meyer, Neu. Jahrb., 1844, p. 335, from the 

 lower Miocene of Weinheim, and for this reason obesus is re- 

 tained. 



Formation and locality. Known chiefly from- the Cretaceous 

 marls. I have examined the following examples : The type from 

 New Egypt in Ocean County (T. A. Conrad) ; the type of My- 

 liobates obesus Leidy from Vincentown (C. H. Budd), both 

 Burlington County; 2 from Mullica Hill in Gloucester County 

 (W. B. Atkinson). [The Hornerstown marl, the Vincentown 

 limesand and the Manasquan marls, all Cretaceous, are the for- 

 mations apparently involved, although the Miocene is known near 

 Mullica Hill, K.] 



Myliobatis kummSli sp. nov. 



Dental plate depressed in form, moderately thick, composed of 

 17 median teeth, and at least two series of lateral teeth. Enamel 

 surface generally slightly convex, with slight median concave 

 longitudinal depression, so that surface is very slightly double 

 convex, with each side sloping down somewhat strongly convex. 

 Median depression concavely so shallow as to scarcely appear 

 concave. Basal surface largely well and evenly convex from 

 median axis, inclining well towards each side. Transverse 

 median sutures posteriorly, rather evenly, though slightly convex, 

 but anteriorly becoming somewhat slightly double convex. Ver- 

 tical diameter of anterior median teeth about one-ninth of hori- 

 zontal diameter, and of posterior teeth much greater. Lateral 

 teeth hexagonal, 13 in one series on right side and two series of 

 10 in the inner and seven in the outer on left side. Though all 

 enameled surfaces smooth median teeth show a number of vertical 

 wrinkles extending more or less transversely over dental area, 

 with pronounced ridge submedianly extending over at least first 

 12 median teeth. This ridge assymmetrical or a little nearer right 

 than left side. At lateral portion of each median tooth are one or 



