79 



by a middle-sized foramen ; deltidium in two pieces, partly surround- 

 ing the aperture ; beak-ridges not very sharply defined ; smaller valve 

 slightly depressed near the front ; surface smooth, strongly punctate, 

 and marked by a few concentric lines of growth ; colour light yellow ; 

 apophysary system composed of a central longitudinal septum, ex- 

 tending to a little beyond half the length of the shell, in the form of 

 a narrow plate somewhat elevated at its extremity, to which and to 

 the hinge plate are attached the calcified riband-shaped lamellae form- 

 ing the loop. Length 4, width 3, depth 2 lines. 



Hab. Spitzbergen. 



Obs. — This small Terebratella seems distinguishable from all the 

 other recent forms of the genus, by its dimensions, regular ovate 

 shape, thinness of shell, and comparatively short, doubly-attached 

 loop, which does not exceed half the length of the valve. I have 

 hitherto been able to examine but one specimen, from the collection 

 of Robert M'Andrew, Esq., and Mr. Cuming. 



6. TerebratulinaCumingii, Dav. 1852. (PI. XIV. fig. 17-1 9.) 

 Diagnosis. — Shell ovate, somewhat pentagonal, nearly as wide as 



long ; valves almost equally convex ; beak small, obliquely truncated 

 by a circular emarginate foramen ; deltidial plates disunited, a small 

 portion of the aperture being completed by the umbo ; auricular ex- 

 pansions on either side of the umbo very small ; surface ornamented 

 by a great number of minute radiating elevated strise, augmenting 

 rapidly by the intercalation of smaller costse at variable distances be- 

 tween the larger ones ; the front margin of the larger valve indents 

 the smaller one ; colour white, tinged with yellow ; structure punc- 

 tate ; internal apophysary supports short and annelliform. Length 

 3^, width 3, depth 2 lines. 



Hab. Chinese Seas. Coll. Cuming. 



Obs. — This little Terebratulina may be easily distinguished from 

 all the other recent species of the genus by its size and relative width 

 and length, being much more convex and globular. 



7. MoRRisiA ANOMioiDES, Scacchi, sp. 1843. (PL XIV. 

 fig- 29.) 



Orthis anomioides, Scacchi in Phil. Moll. Sicil. ii. 



Terebratula appressa, Forbes, Report on the MoUusca and Radiata 

 of the iEgeau Sea, 1843. 



Diagnosis. — Shell minute, circular, depressed ; foramen large, 

 round, encroaching equally on both valves ; larger valve veith a 

 straight hinge-area ; deltidial plates minute, widely separated ; 

 smaller valve deeply notched at the umbo ; apophysary system con- 

 sisting of two branches originating at the base of the dental sockets, 

 and united to a small elevated process arising from the centre of the 

 valve. 



Animal furnished with two subspiral or sigmoid arms fringed with 

 comparatively large ciha ; the shell is of a green colour, with bright 

 orange ovaries contrasting with the brilliant white of the ciliated arms ; 

 structure punctate. Length 1, width 1^, depth \ line. 



Hab. Mediterranean; depth 9.') fathoms (Forbes). 



