260 Annals of the South African Museum. 



more strongly curved. The surface is convex, rather tumid, 

 especially anteriorly and near the beak, which is broad, obtuse, 

 swollen, incurved, apparently rising a little above the hinge-line, and 

 situated between one-third and one-half the length of the shell from 

 the anterior end. The clavicular ridge is strong, curved, concave 

 forwards, and extending fully three-fourths across the valve, and arises 

 just in front of the beak ; and there is the trace of a second ridge 

 half-way between the usual one and the posterior end. The surface 

 is ornamented with rather strong equidistant concentric wrinkles 

 and finer striae. 



Dimensions. — Length 16 mm. ; height 10 mm. 



Affinities. — The figures given by Beushausen '•' of a young indi- 

 vidual of Cucullella elliptica, Maur., resemble this specimen in 

 general shape, and have the peculiar second internal ridge behind 

 the usual clavicular one. But the beak in our specimen is not so 

 anteriorly placed, and is also more tumid. 



Locality. — (No. 69) Ezel Fontein, Ceres. 



NUCULITES MAETIALIS sp. nov. 

 (PI. XXXII., fig. 2.) 



There is one cast (No. 103) of the left valve of a species of 

 Nuculites which certainly belongs to a new species, but it is too 

 imperfect for a full description. The shell is suborbicular, very 

 tumid, especially near the umbo, which is large, obtuse and 

 apparently situated about one-third the length from the anterior end. 

 The anterior and basal margins are strongly arcuate ; the posterior 

 margin is broken, but seems to be obliquely truncate at the upper 

 angle. The hinge-line is not well preserved. There is a deep 

 strong clavicular ridge, nearly vertical, slightly curved forwards, 

 starting just in front of the umbo and reaching about three-fourths 

 across the shell. 



Dimensions. — Length about 45 mm. ; height about 35 mm. ; depth 

 of valve near umbo 11 mm. 



Affinities. — The characteristic features of this shell are its suborbi- 

 cular shape, and its tumid strongly convex surface. There seems to 

 be no closely allied species with which it can be compared. N. 

 triqueter, Hall, t from the Hamilton Group, is a form somewhat 

 resembling it, but it is too obliquely truncated behind. 



Locality. — (No. 103) Ezel Fontein, Ceres. 



* Beushausen, oj;. cit., p. 104, t. v., figs. 13, 13r;, 14. 



t Hall, op. cit., pi. xlvii., figs. 17-28 ; pi. xeiii., figs. 8-10, p. 3'26. 



