252 APPENDIX. 



the ligament, have been dredged by Mr. M'Andrew, in from forty 

 to sixty fathoms of water, near the Great Fish-bank in the North 

 Sea, about one hundred and forty miles from the nearest land ; 

 others were also taken by him at various distances from the 

 Northumbrian coast. 



It is the shell termed calcarea * in Mr. Hanley's Monograph 

 of Tellina, and chiefly differs from the typical form of proxima in 

 being much more elongated, and all but equilateral. An en- 

 larged experience of the variation permitted to each species, and 

 an anxious wish to avoid any unnecessary addition to the names 

 in our Fauna, induce us to regard it provisionally as a variety of 

 proxima. 



The specimen, which measures an inch and a quarter in 

 length, and an inch and five-sixths in breadth, is precisely 

 similar to an example that we received from the Gulf of St. 

 Lawrence. It is subovate, moderately convex, somewhat bent, 

 rather strong, of an opaque and chalky white on both sides, 

 clothed with a dark ash-coloured epidermis, and is irregularly 

 and slightly wrinkled in a concentric direction. The ventral 

 margin is retuse in the middle, but judging from the lines of 

 increase, this is not the case in the earlier stages of growth ; it 

 is more arcuated and ascending in front, than behind. The 

 anterior side is slightly the longer, and is well rounded at its 

 extremity ; its dorsal edge, except near the acute and prominent 

 beak is convex, and but moderately declining ; the dorsal slope 

 is straighter and more decided on the posterior side, whose 

 extremity is bluntly wedge-shaped. Neither the umbonal ridge 

 nor the ventral flexure are conspicuous. The ligament is large 

 and somewhat projecting. The hinge has no lateral teeth, and 

 merely displays a narrow bifid primary one in front, with a still 

 thinner simple one behind it. The siphonal scars are profound 

 and large ; the pallial sinus is ample and elongated. 



* T. sordida, Philicpi, Ncue Conch, vol. ii. pt. 9, pi. 5, f. 6. — T. calcarea, 

 Hanl. (as of Chemnitz, whose species is far from clear) in Sowerby, Thesaur. 

 Conch, vol. i. p. 314, pi. 62, f. 1«3.— r. lata, Lovkn, Ind. Moll. Scandin. p. 41 

 (as of Gmelin, w^hose species is solely derived from Lister's figure). — Middend. 

 Sibiris. Reise, vol. ii. pt. 1, pi. 23, f. 4, 5. 



