244 Bulletin 31 244 



PLATE 43 



Figure Page 



I. Meretrix sylvcBvupis . n. sp., 20 mm 136 



A Sabine, Woods Bluflf specimen, here incorporated to show 

 the development of the perovata stock more completely. 



2, 3. j'l/. 52/1?'/ ;«/>ri?55a Con., Pope's Cr., Md 136 



Fig. 2, 17 mm. 



3,25 " from the Virginian basin, inserted to show 

 related members in the perovata stock. 



4-7. M. nejisensis, n. sp.. Neuse River, N. C 136 



Fig. 4,43 mm. ; from a gutta-percha mold, showing heavy 

 dentition, deep muscular impressions and sub-bi- 

 angular pallial sinus. 



5, 33 mm., also from a mold ; abbreviated posteriorly 

 by disease. 



6, 50 mm. ; a somewhat restored, full-grown specimen 

 showing form and exterior undulations. 



7, 35 mm. ; showing form and umbonal liration. 



7, a, 33 '■ a nearly complete silicious pseudo-morph 

 with nearly smooth exterior. 

 8, 9. AT. perovata, var. lisbonensis, n. var., Lisbon, Ala 137 



10. M. neusensis wslt. approaching /»^rt»ya/a 137 



Mold of a Neuse river form approaching the short subvitrea 

 form of perovata. 



11. M. perovata, war. subvitrea de Greg., 29 mm., Lisbon 138 



12-14. 3f. perovata Con., Claiborne 138 



Fig. 12, 45 mm. 

 13. 44 " 

 13 a, 45 " 

 14- 30 " 



1.5-16. AI. Diortoni Con., Claiborne 139 



Fig. 15, 32 mm. 

 16,8.5 " 



17. y)/. />i?rot'«/a, var. a/fl'r/V/n' Har., Claiborne 138 



View from the anterior. 



