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

 our new form being similar to that of Ter. aiistralis 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. Terebratklla BoucHARDii, Dav. 1852. (PI. XIV. fig. 4-6.) 



Diagnosis. — Shell of a suborbicidar 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 

 Adams and Reeves principally in the form of its beak and in its 

 coloration ; the Corean form is beautifully strigated with vivid red, 

 while Ter. Bouchardii is of a uniform light yellow colour ; the details 

 of the loop seem Ukewise to differ a httle. 



3. Terebratella Evansii, Dav. 1852. (PL XIV. fig. 7-9.) 



Diagnosis. — Shell subovate, longer than wide ; perforated valve 

 most convex, smaller one rather compressed ; beak tapering, not much 

 recurved, and obliquely truncated by an emarginate foramen ; del- 

 tidia small ; beak-ridges well defined, leaving between them and the 

 hinge-margin a false area ; surface ornamented by a few unequal bi- 

 furcated and intercalated costse ; colour pale red ; structure punc- 

 tate ; apophysary system composed of a central longitudinal sep- 

 tum, not exceeding half the length of the valve, arising rapidly in the 

 form of a narrow elevated plate, almost reaching the centre of the 

 perforated valve, to the middle of which, and to the crural base, are 

 doubly attached the calcareous riband-shaped lamellae forming the 

 loop. Length 4, width '5\, depth 1|^ lines. 



Hah. New Zealand. Coll. Cuming. 



Obs. — On first inspection, I thought this shell, of which Mr. Cuming 

 has two examples, might be the young of Terebratella Zelandica ; but 

 on examming the calcareous appendages, I found great dissimilarity in 

 their respective details. In Ter. Zelandica the loop is first fixed to the 

 hinge plate, and again, by a transverse shelly horizontal process, to 

 the extremity of a slightly elevated mesial septum ; the lamella pro- 

 ceeding again before bending back, as in all Terebratella : but in the 



