1866.] GUPPY JAMAICAN MOLLUSCA. 293 



49. Caedita scabricostata, spec. nov. PI. XVIII. fig. 10. 



Shell suborbicular, nearly as high as wide, with about 18 regularly 

 nodosely muricate impressed ribs ; posterior margin nearly straight, 

 forming an angle with the ventral margin, which is rounded ; ante- 

 rior margin rounded ; umbones prominent ; margins strongly crenate , 

 hinge with two teeth, of which the posterior one is long and narrow. 



50. Cardium Haitense, Sow. 



Quart. Journ. Geol. Soc. vol. vi. p. 52, pi. 10. fig. 11. 



51. Cardiijm lingua-leonts, spec. nov. PI. XYIII. fig. 7. 



Shell elongate, subquadrate ; valves deep, ornamented with nume- 

 rous (32) nodosely muricate ribs, which are lower and more distant 

 towards the anterior and posterior margins ; margins coarsely cre- 

 nulate, the posterior one strongly serrate : hinge with three large 

 and stout teeth. 



The nearest ally of this shell is C. ruhicundum of Madagascar. It 

 is distinguished both from that species and from C. elongatum by its 

 deeper valves and by the ribs on the disk being somewhat muricate. 

 It is also rather narrower than those species. 



52. Carditjm inconspicuum, spec. nov. PI. XYIII. fig. 12. 



Shell elongate, sub trigonal, orate, ornamented with numerous (38) 

 imbricate radiating ribs broader than their regularly squamose in- 

 terstices ; umbones scarcely prominent ; margins strongly dentate ; 

 hinge small, with three teeth. 



53. CoRBULA vniiNEA, spec. nov. PI. XYIII. fig. 11. 



Shell thick, transversely oblong, rounded anteriorly, produced 

 posteriorly into an acute beak ; valves ornamented with stout, rather 

 round, concentric ribs ; hinge with a single prominent tooth and a 

 deep orbicular pit in front of it. 



54. Pecttjnculus pennaceus. Lam. 



Lamarck, Anim. sans vert. (ed. Desh.) vol. vi. p. 490 ; Eeeve, 

 C. I. Pectunculus, No. 24. 



55. Pectunculus acuticostatus, Sow. 



Quart. Journ. Geol. Soc. vol. vi. j). 53, pi. 10. f. 13. 



56. Arca consobrina. Sow. 



Quart. Journ. Geol. Soc. vol. vi. p. b2, pi. 10. fig. 12. 



57. Arca N"o^, Linn. 



Syst. Nat. p. 1140 ; Peeve, C. I. Arca, No. 72. 



Abundant in most of the West Indian later Tertiaries, and in the 

 existing seas. 



58. Arca in^quilateralis, spec. nov. PI. XYIII. fig. 2. 



Shell transverse, slightly oblique, very inequilateral, produced 

 posteriorly ; valves with about 30 crenate radiating ribs, single on 



