54 DE. T. DAVIDSON ON EECENT BEACHIOPODA. 



circular foramen laterally margined by two small disunited deltidial plates. Cardinal 

 process prominent, and formed of three distinct parts. In the interior of the dorsal 

 valve, and under the incurved extremity of the umbo and hinge-plate, there rises a 

 wide short and massive septum, and on either side on the bottom of the valve the 

 muscular scars are visible. Loop delicate, elongated and reflected. Shell-perforations 

 numerous. Length 2 inches, breadth 1 inch 4 lines, depth 1 inch 2 lines. 



Hah. It was dredged by the ' Challenger ' Expedition in great numbers ofi" Marion 

 Island, west of Kerguelen Island, at a depth of 100 fathoms. Two examples oi Platydia 

 anomioides were attached to one of the specimens. Also at Balfour Bay, near 

 Kerguelen Island, in 20 to 60 fathoms, south of the same island at a depth of 150 fathoms. 

 Three examples of Wiynclionella nigricans, var. pixidata, were obtained with it. 



Obs. I have examined several specimens of the animal that had been dredged alive by 

 the expedition, as well as of the shell from 1 line up to 24 lines in length. Some examples 

 were nearly circular and as broad as long, bvit the larger number were of an elongated 

 oval shape, becoming ventricose with age. When the peduncle by which the shell 

 adhered to foreign bodies was sufiiciently long, and did not interfere with the animal's 

 limited movements, the beak was much incurved and the foramen small ; but in most 

 cases the peduncle was exceedingly short, and the shell came into contact with the hard 

 bodies to which it was moored, causing erosion and the consequent enlargement of the 

 foraminal aperture. The animal closely resembles in general character that of Wald- 

 heimia Jlavescens, so admirably described by Owen and Hancock. 



Some specimens bear a certain resemblance to Waldlieimia lenticularis ; but this last 

 is smaller, more ovate or regularly oval, and more especially in the young and inter- 

 mediate stages of growth. Having forwarded two examples for Mr. Ball's examination, 

 he informs me : — " I have carefully compared it with d'Orbigny's Waldheimia Fontaineana, 

 and feel more sure than ever of the correctness of my reference of his species to 

 Waldheimia venosa. It is certainly not this fine species ( Waldheimia kerguelenensis)," 

 though it is possibly identical with the shell erroneously described and figured by G. B. 

 Sowerby, at p. 359, and plate xxi. figs. 99-101, of his ' Thesaurus Conchyliorum,' in 

 1846, as the Terebratula glohosa, Lamarck. The specimen Sowerby figured under that 

 name (said to have been taken from Lamarck's collection) is now in the British Museum, 

 and Sowerliy was certainly mistaken in stating " It agrees perfectly with the represen- 

 tation in the ' Encyclopedic Methodique,' tab. 339. fig. 2 " ! 



30. Waldheimia Gbayi, Davidsou. (Plate X. figs. 1-4.) 



Terebratula Grayi, Davidson, Proc. Zool. Soc. 1852, p. 7(\, pi. iv. figs. 1-3. 



Terebratula [Waldheimia) Grayi, L. V. Schrenck, Reiseii mid Forschungem in Amur-Lande, p. 465, 

 1854-56. 



Waldheimia Grayi, E. Suess, Sitzungsb. Akad. Wissenschaften, Bd. xxxvii. p. 201, 1859. 



Terebratula [Waldheimia) Grayi, L. Reeve, Couch. Icon. pi. 2. figs. 5 a, b, c, 1860, and Ann. & 

 Mag. Nat. Hist. 3rd ser. vol. vii. p. 175, 1861 ; Journal de Couchyl. p. 123, 1861. 



Waldheimia Grayi, Carpenter, Rep. Brit. Assoc. 18G3, p. 636. 



