OF CONCHOLOGY. 121 



thick, prominent, bifurcate at its extremity, and serrated on its 

 anterior edge. The bifurcation is the first indication of the 

 septal processes which are the last to be calcified, and when the 

 extremely thin haemal processes are yet incomplete the young 

 shell closely resembles a Magas. In the beak of the neural 

 valve just inside the foramen is a very prominent thin lamina or 

 septum which half closes the foramen. In the adult the mus- 

 cular system is not largely developed. The pedicel muscles are 

 the strongest. The cardinals are slender and their bases are 

 spread over a wide extent of the neural valve, but the muscular 

 impressions are imperceptible. The adductors are small and 

 slender. The brachia follow the lateral loops of the apophyses 

 and cross below the mouth on the reflected portion and the septal 

 processes. There is no central spiral lobe. The fringes are in 

 a single row, flattened and extremely thin ; in an adult they 

 are about -13 in. long. They are much more slender than in 

 TerehratuUna or Megerlia. When fully extended they are far 

 from the margin of the valves. The mouth is circular, situated 

 between the adductors. The visceral part of the system is pro- 

 tected by a thin tough membrane. The color of the animal is 

 reddish or brownish, the ovaria vary in the same way. The peri- 

 visceral fluid is of a reddish-yellow color. 



The umbones of both valves are generally eroded by contact 

 with stones. The animal seemed to have the power of turning 

 half around on its peduncle at will. 



Terebratella coreanica. Ad. and Rve. 



Terehratula coreanica, Adams and Reeve, Voy. Lam. 1850, 

 p. 71, pi. xxi, fig. 3. Rve., Conch. Ic. vii, fig, 28, a, b. 



Terehratula miniata, Gld., Proc. Boston Soc. Nat. Hist. 1861, 

 p. 323. Suess., Vienna Acad. 1859, p. 206. 



Terebratella coreanica, Dav., Ann. Nat. Hist. 1852, p. 367. 

 Schrenck, R. v. Amurl. 1867, p. 468. Rve., Journ. de 



cannot be accepted until further information is obtained. The same may 

 be said with regard to Waltonia ( Valenciennesii) Dav. The latter genus 

 has been withdrawn by the author, and the specific name rather hastily 

 applied to the mature form described by the same gentleman (in the P. 

 Z. Soc. 1852, p. 77, pi. xiv, fig. 7-9,) as Terebratella Eoansii. While it 

 is not impossible that the two are identical, still it would seem unneces- 

 sary to reject a name applied to a mature and unmistakable species for 

 one given to a young shell which could hardly be identified without the 

 aid of a very large series of individuals of various ages. The references 

 are as follows : 



Gwynia {capsula Jeffreys) King, Proc. Dub. Univ. Zool. and Bot. 

 Assoc. Vol. i, 1859, p. 258, fig. 1 to 5. Rve., Conch. Icon. pi. x. fig. 39. 



Waltonia (Valenciennesii) Dav., An. Nat. Hist. 1850, p. 475. lb. 1852, 

 p. 372. Gray, B. M. Cat. p. 101. Dav., An. Nat. Hist. 1861, p. 38. 



