92 TKSTACEOUS MOLLUSCA. 



CYRENA. 



Shell roundinh and ti'igonal ; turgid or ventricose, inequilateral, 

 solid, with a strong epidermis, and the beaks usually decorticated ; 

 hinge with three teeth in each valve ; lateral teeth almost always 

 two, one of which is near the primary ones ; ligament external, 

 and placed on the larger side. 



* Lateral teeth serrated or denticulated. 



C. Trigonella. La7n. 1. Smallish, triangular, sub-equilateral, 

 fulvous and nearly smooth, beaks somewhat violet. 4. — £J. Indies. 



C. Orientalis. Lam. 2. — Del. t. 7. f. 8. Transverse, sub- 

 triangularly ovate, olive green, the beaks violet, with transverse dis- 

 tant grooves : violet within, the lateral teeth serrulated, f . — China. 



C. Cor. Lam. 3. — Del. t. 7. /• 7 . — Tellina Fluminalis. 

 MvUer.^D. p. 106.— C/i. /. 320.—^. t. 302. /. 2.— Venus F. 

 W. t. 8.f. 1 13. Elongated heart-shaped, oblique, fully as long as 

 broad, anteriorly longer and rather attenuated, thick, tumid, cuticle 

 olive greeu with often olive brown zones, with distant sub-imbricated 

 grooves : beaks prominent and involute : inside violet. Ij. — 

 Euphrates. 



C. FuscATA. Zam. 4. —Tellina Fluviatilis. D.p.l07. — 

 Ch.f. 32l.~E. t. 302. f. 2.— Venus F. W. t. 8./. 1 15. Trans- 

 verse, olive green, sub -equilateral, rounded at the sides, not thick, 

 with close sub-imbricated grooves ; beaks obtuse : violet within. 

 1. — Canton. 



C. Fluminea. Lam. b. — Tellina Fluminea. Ginel.32A3. 

 —D. p. 107.— Ch. f. 322, ^.—Brhroi. Fluss. t. 4./. 2.— Venus 

 F. W. t. S.f. 114. Heart-shaped, gibbous, yellowish-green, girt 

 with transverse broad grooves ; within mottled with white and 

 violet, hinge with the lateral teeth finely denticulated. 1. — China. 



C. ViOLACEA. Lam. 7.— Del. t. 7. f. b.—E. t. 301./. 1. 

 Ovate elHptic, inequilateral, transversely grooved, violet within and 

 without, indistinctly rayed ; anterior side convex and acute, the 

 beaks decorticated ; hinge with the lateral teeth denticulated. \^. 

 — The figures represent a muck larger specimen. — Indian Ocean, 



C. LiMOSA. Gray. Ann. Phil. 25.— Tellina L. Maton. 

 Lin. T. 10. t. 24./. 8, 9. \0.—Wood. G. C. t. 46./. 4, 5.— D. 

 p. 106. — W. t. 5. /. 86. Ovate, equivalve, brittle, smooth, trans- 

 versely striated, with a green cuticle and the margin entire ; um- 

 bones prominent and rather acute : within purple. ^ . . |. — S. 

 America. 



C WooDiANA. Lea. Tr. Am. Ph. 5. t. 18./. 55. Sub-tri- 

 angular, ovate, thick, obtusely angular, anteriorly sub- equilateral, 

 convex, shining except on the anterior slope, blackish brown, with 

 transverse large wrinkles : beaks large, rounded : inside white, car- 



