Dr. A. Smith Woodward— Fish-remains, Brazil. 195 
Cretaceous Pftychodus. The teeth are well described by Cope, but the 
illustrations of them now given are needed for the satisfactory under- 
standing of their characters. The lateral ends of the median teeth 
(Fig. 4) are as irregular in their bevelling and truncation as those of 
Ptychodus; and the shape of the side-teeth (Fig. 5) must doubtless 
have been equally irregular. The appearance of the vasodentine is 
remarkably similar to that.of Ptychodus ; and the enamelled surface of 
the flattened crown bears wrinkling (Fig. 44) suggestive of that round 
the borders of the teeth of Ptychodus, but all the wrinkles are directed 
antero-posteriorly, and there is no transversely ridged central area. 
As described by Cope, the root is sharply constricted from the crown 
(Figs. 4a, 5a), and it differs from that of the teeth of Péychodus in 
being very slightly marked on its lower face (Fig. 5) with a few broad 
antero-posterior grooves. There is evidence of at least three paired 
lateral series of teeth, which rapidly diminish in size outwards. 
Apocopodon sericeus occurs in the Cretaceous of Maria Farinha, 
Province of Pernambuco. 
R#INOPTERA PRISCA, sp. noy. (Pl. VII, Figs. 6, 6a, 7, 7a.) 
Vertebree from the Chalk of Aix and Maastricht are supposed by 
Hasse to be referable to Rhinoptera, but no teeth of this large skate have 
hitherto been recorded from Cretaceous formations. ‘lwo fragments of 
dentition, apparently of Rhinoptera, from the yellow limestone of 
Maria Farinha, are therefore of much interest. 
The most important of these two specimens is shown from the oral 
aspect, of the natural size, in Fig. 6, and comprises two median teeth, 
with remains of four paired lateral series. All the teeth are bevelled 
at the ends in the usual manner, and their coronal surface is flattened 
or very slightly convex. The superficial layer of the crown has been 
accidentally removed from all the teeth except one in the outermost 
row, where it is shown to have been roughened by a fine network of 
wrinkles (Fig. 6a). The root of each tooth is traversed by the usual 
antero-posterior grooves, but, as well shown in a second example of 
a median tooth (Figs. 7, 7a), these grooves are comparatively few with 
relatively large intervening ridges. The median teeth preserved are 
nearly three times as broad as long; the teeth of the first paired series 
are about twice as broad as long; those of the second paired series are 
irregular rhombs as broad as long; while the teeth of the:two outer 
paired series are comparatively small, narrow, and antero-posteriorly 
elongated. ‘he antero-posterior measurement of each tooth preserved 
is from 7 to 8mm., and the width of each tooth is as follows :— 
median, 22mm.; Ist lateral, 15 mm.; 2nd lateral, 8mm.; 3rd lateral, 
6mm.; 4th lateral, 5mm. 
f. prisca is readily distinguished from the oldest species of 
Rhinoptera hitherto described, namely, 2. Daviest, from the London 
Clay of Sheppey,' by the flatness of the coronal surface of all the 
teeth, and by the relative proportions of the lateral teeth. It agrees 
with this species, however, and differs from all others, in the peculiar 
reticulating wrinkles on the coronal surface of the teeth. These 
1 A.S. Woodward: Cat. Foss. Fishes Brit. Mus., pt.i (1889), p. 126, pl. iii, fig. 6. 
