DE. T. DAVIDSON ON EECENT BEACHIOPODA. 91 



and in no way related to Terehratella dorsata. I may, however, remark that I have 

 smooth examples of T. dorsata that I could scarcely distinguish from the figures of 

 Gould's specimen. Gould's types can all he seen in the National Collection at Wash- 

 ington. Dr. Gould says that the surface of the shell, when examined by the aid of a 

 lens, is tessellated with elongated dots arranged in quincunx, which seem to he specks of 

 opaque white coloiu* rather than punctures. T. jndvinata m.ust, however, for the present, 

 be looked upon as a doubtful so-termed species. 



47. Terebratella (?) bubiginosa, Dall. (Plate XVI. fig. 19.) 



TerebrateUa ?, Dall, Amcr. Jouru. of Conchology, vol. vi. p. 122, pi. vi. fig. 4, 1870. 



Terehratella suffusa, Dall, Amer. Joui-u. of Concliology, vol. vii. p. 65, 1871 (not of Reeve). 

 TerebrateUa rubiyinosa, Dall, ibid. vol. \'ii. p. 65, and Proc. Acad. Nat. Sci. Philadelphia, 187.3, 

 p. 185. 



Shell almost circular, about as broad as long ; margins fiexuous. Dorsal valve mode- 

 rately convex, with a faint depression near the middle of the margin, but which is not 

 noticeable in the younger portions of the valve. Ventral valve convex, rather deeper 

 than the dorsal one ; beak short, slightly incurved and truncated by an incomplete round 

 foramen, margined by the umbo of the dorsal valve, and by two very small rudimentary 

 lateral deltidial plates. In the interior of the dorsal valve the loop is long and doubly 

 attached, first to the base of the hinge-plate, and then to a short mesial septum. Surface 

 smooth to within a short distance from the margin, when the valve presents a few irregular 

 rounded areas. Colour a rather light brown. Length 1 inch 1 line, breadth about the 

 same. 



Hah. ? Cape of Good Hope. (?? Types in the Smithsonian Cabinet.) 



Ohs. I am very doubtful with respect to the specific value of this species. In 1870, 

 Dall referred it with uncertainty to the Terehratella suffusa of Reeve (Conch. Icon. pi. v. 

 fig. 18), but after my subsequently sending him Reeve's type of T. siffusa for examination, 

 he wrote back that as Reeve's type is possessed of a lai'ge elevated septum and loop Hke 

 Magasella, he has given the name Terehratella ruhiginosa to his species. In his de- 

 scription of the shell he informs us that " the crura are small, slender, short, and acute. 

 The loop processes are exceedingly slender, mere threads in fact, and roundly deflected 

 outward at first ; bending inward just before the neural bend, they give off two 

 moderately broad septal processes, which meet each other at the end of the septum at 

 an angle of 60° (not at right angles to the septvim and behind its end, as in T. dorsata 

 or chilensis). The main processes are then deflected neurally, and the extreme 

 ' bight ' of the loop is straight and somewhat angulated at each side. The perforations 

 externally are moderate, arranged in quincimx order, .smaller and more regular than in 

 T. dorsata, which is its nearest analogue." 



Never having seen any specimen of T. ruhiginosa, I can only reproduce Mr. DaU's 

 statements upon the subject. He says that the species appears to him to be perfectly 

 distinct from any other described Terehratella. The loop he figures is certainly very 

 peculiar in its mode of attachment to the short mesial septum. 



SECOXD SERIES. — ZOOLOGY, VOL. IV. 13 



