Molliisca from, the Bokkcceld Boils. 265 



length of the shell from anterior end, obtuse, low, rising only a little 

 above hinge-line. Faint undefined shallow sulcus runs obliquely 

 across shell from just behind umbo to the weak sinus in posterior 

 inferior margin. Hinge-line about two-thirds the length of the 

 shell, with 8-9 small transverse teeth in front of beak, about 25 

 smaller ones behind beak, and several slender ones arranged in 

 a fan-like fashion between the beaks. Surface ornamented with 

 concentric striie, coarser near margin. 



Dimensions. — Length 65 mm. ; height 38 mm. 



Affinities. — In shape this shell is more elongated than P. antiqiia, 

 (Sharpe) ■•'■ ; the beaks are more forward ; there is an inferior sinus 

 at the posterior end, but no dorsal one. P. riidis, (Sharpe), i is a 

 shorter, broader shell with the posterior end not produced, but it has- 

 a similar sinus and a faint sulcus across the surface. 



Localit I/. —{N OS. 85, 86, 87) Ezel Fontein, Ceres. 



PAL.EONEILO aff. CONSTEICTA (Conrad). 

 (PI. XXXII., figs. 5, 5a.) 



One specimen (No. 95) of a small shell belonging to PaUeoneilo 

 shows the two valves as casts in apposition, but only the left one is 

 at all well preserved. The shape is broadly ovate ; the anterior end 

 short and abruptly rounded ; the basal margin is strongly curved 

 (not well seen) ; the cardinal margin is gently arcuate and scarcely 

 oblique ; the posterior end is broken and its shape cannot be deter- 

 mined. The umbo is very forwardly situated, being only about one- 

 fourth or one-fifth of the length of the shell from the anterior end,, 

 and is directed forwards, rising rather prominently above the hinge- 

 line. The valves are gently convex, most so towards the front end 

 and the umbo ; a marked sulcus widening posteriorly runs obliquely 

 backwards behind an undefined rounded umbonal ridge from just 

 behind the umbo to the posterior basal margin. There are 6-8 

 transverse teeth in front of the umbo, several more slender ones 

 arranged in a fan-like fashion below the umbo, and 12-15 rather 

 coarse transverse ones behind. 



Dimensions. — Length 16 mm. ; height 11 mm. 



Affinities. — The closest relations of this form are to be found in 

 Palceoneilo constricta (Conr.) I and the smaller examples of P. orbignyi, 



* Sharpe, op. cit., p. 210, pi. xxvii , tig. 1. 



t Ihid., p. 211, 111. xxvii., tig. 6. 



I Hull, '-/). fit., pi. xlviii., figs. 1-16, p. :«3 ; pi. li., tig. 17. 



