146 Zoological Society. 



figures, synonyms, dates, &c, is still a desideratum, and I hope ere 

 long that the science of Conchology will be enriched by such a valu- 

 able and necessary contribution. 



The only object of this short paper is to describe some unfigured 

 forms, to which I have added some remarks on a few species not 

 hitherto completely understood. 



1. Terebratula Grayii, Dav. 1852. 



Diagnosis. — Shell irregularly pentagonal, rather broader than long; 

 valves unequally convex (the perforated being gibbous and the smaller 

 valve rather flattened) ; beak not much produced, truncated by a very 

 large emarginate foramen — the deltidial plates are disunited, a small 

 portion of the aperture being completed by the umbo ; hinge-line 

 straight; beak-ridges sharply defined, leaving between them and the 

 hinge-margin a wide, almost flat area ; surface ornamented by a great 

 number of irregular and unequal radiating costse, augmenting rapidly 

 from numerous bifurcations and intercalations of smaller plaits be- 

 tween the larger costse ; colour partly yellow and red, this last be- 

 coming more vivid as it approaches the concentric lines of growth ; 

 structure punctate ; internal appendages consisting of a simply 

 attached loop, the riband-shaped lamella extending to about four- 

 fifths of the length of the shell before bending back on itself. Di- 

 mensions variable: length 14, width 15, depth 9 lines. 



Hob. Coast of Korea. Coll. Cuming. 



Obs. — This fine species has been known to me for several years, but 

 unobserved by other collectors, who erroneously supposed it to be 

 the Ter. rubra of Pallas, to which it bears some external resemblance, 

 but is essentially different in its internal arrangements ; the loop of 

 our new form being similar to that of Ter. Australis or Ter. lenticu- 

 laris, &c, while the appendages of Ter. rubra, which is the type of 

 my lately proposed genus Kraussia, consist only of two central diver- 

 ging branches, somewhat spread out at their extremities. Ter. Grayii 

 is also distinct from Terebratella Zelandica, the loop of this last being 

 doubly attached, as in all the species of that section. 



2. Terebratella Bouchardii, Dav. 1852. 



Diagnosis. — Shell of a suborbicular or trapezoidal form, longer 

 than wide, or broader than long ; perforated valve most convex, late- 

 rally compressed and keeled, the imperforated valve presenting a lon- 

 gitudinal depression extending from about the middle of the valve to 

 the front ; beak produced, recurved and truncated by a large circular 

 and entire foramen ; deltidium in two pieces, meeting at the umbo ; 

 beak-ridges defined, leaving between them and the hinge-margin a 

 slight concave false area ; surface smooth, interrupted only by a few 

 concentric lines of growth ; colour light yellow ; internal calcareous 

 lamellae fixed first to the crural base, and again to the longitudinal 

 mesial septum, before attaining their greatest length and bending back 

 on themselves to form the loop; structure punctate. Length 14, 

 width 13, depth 8 lines. 



Hab. Unknown. Coll. of Mr. Cuming. 



Obs. — This species seems to differ from Terebratella Coreanica of 



