1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 729 



transversa wliicli has the flexure, though obscure, in the same sense as 

 T. transversa. This is the T.gouldii, Dall,* of which, for comparison, 

 figures are given (pi. xxx, fig. 2; pi. xxxii, fig. 10). T. gonldii was first 

 described from a specimen in the Magasella stage, in 1871, but a com- 

 parison of specimens twenty years later showed that the adult form 

 was a Terehratalia. But T. gouldii is a thinner and flatter shell, with 

 the ribbing finer and more regular, as well as more distinctly marked, 

 than in T. transversa. It is i)ossible that future search may reveal T. 

 gouldii on the American shores of the Pacific, as TerebratuUna Miensis 

 has been fouud so distributed. At present only a few specimens are 

 known. The color is of a livid grayish white, much like many sx^eci- 

 mens of T. transversa. 



TEREBEATALIA OCCIDENTALIS, Dull. 

 Plate XXXI, figs. 7,8. 



Terebratella oeeidentalis, Dall, Proc. Cal. Acad. Scl.,iv, p. 182, pi. i, fig. 7, 1871; 



Proc. Acad. Nat. Sci. Pliila., 1873, p. 184, aud 1891, p. 173, pi. iv, figs. 8, 9 (not 



6 aud 7). 

 Terebratella transversa, var. oeeidentalis, Daaidson, Mou. Eec. Eracb., p. 79, pi. 



XVI, fig 13 (only), 1887. 



Stations 2922 and 2081, in 45 to 47 fathoms, sand, off San Clemente 

 Island, California, in 1889. Monterey, Catalina Island and vicinity, 

 Dall, Cooper, and Caufield, chiefly from the beach. Nos. 401, 123144, 

 aud 95850, U.S.K".M. 



This species is not known from north of Monterey. It seems to be a 

 rare shell, and all the specimens yet examined are radiately ribbed 

 with about ten very conspicuous ribs, more or less tinged with carmine, 

 while the channels between them (and the body of the shell) are pure 

 white. The mesial flexure is exactly the rever.se of that in T. trans- 

 versa^ the brachial valve having it strongly convex, and the pedicle 

 valve concave. The extreme dimensions yet observed are those of the 

 specimen figured here; height 26, width 30, diameter 22 mm. The fig- 

 ures representing this species in the paper r(^ferred to under the last 

 si3ecies were transposed with those representing T. transversa, as indi- 

 cated in the synonymy. 



Explanation of Plates. 



PLATiS XXIII. 



Fig. 1. Halicardia fiexuosa, Verrill, about twice natural size; diagram of the body 

 from below; tbe mantle, i, i, i' , i', severed and turned back to expose the parts; 

 a, position of the anterior adductor; 2^}p'> aduate palpi; /, pedo-visceral mass, 

 supporting the functional foot with byssal groove and the fin-like opisthopodium 

 below (behind) it, aud surrounded by the branchial septum; s, siphoual septum; 

 V, circular valve of the incurrent siphon; x, cavity of the siphon; c, posterior 

 commissure of the mantle lobes. Drawn by W. H. Dall; page 697. 



* Proc, Phil. Acad. Sci., 1891, p. 167. 



