DE. T. DAVIDSON ON EECENT BEACHIOPODA. 191 



or less developed and projecting rostcUum. These extremes, however, will vanish wlicn 

 a number of specimens are examined, and every intermediate form will be found 

 connecting the two extremes. The intimate shell-structure of Crania turhinata 

 seems very much the same as that of C. anoniala, but when describing the structure 

 of the attached valve of C. anomala. Prof. King observes, " Crania ringens (Hoeniug- 

 haus) [iin'bii/ata, Poli] has afforded me more information ; inasmucli as the same 

 valve, which is thick, and adhering to coral, shows, in a vertical section, the perfo- 

 rations distinctly passing direct downwards, and traversing nearly its entire thickness ; 

 becoming forked and attenuated as they approach the attached surface." 



I know nothing of the species (?), which Sowerby and Pueeve erroneously, I think, 

 refer to the Crania rostrata of Ilccninghaus *. 



Sowerby and Reeve describe it as follows : — " Shell with the lower valve rotundately 

 subtrapczoidal, posterior margin rather straight, posterior scars orbicular, the anterior 

 small, semilunar, anteriorly coalescing, rostellum small, rather sharp, disk sinuated, rim 

 grained, anteriorly irregular, thickened ; upper valve thinner, white, somewhat radiately 

 roughened, interior with two raised ribs radiating from the centre towards the posterior 

 margin." 



No fresh observations have been made on this species since the publication of Mr. 

 Sowerby's monograph of the genus in 184-6, and his characters are copied by Reeve 

 verbatim. Its habitat, Mr. Cuming informs me, is " not the Mediterranean, as given by 

 Sowerby, but South Africa." 



104. Crania japonica, Adams. (Plate XXVII. figs. 10, 11.) 



Crania japonica, A. Adams, Ann. & Mag. Nat. Hist. vol. xi. p. 100, 18C3 ; Davidbon, Proc. Zool. Soc. 

 p. 311, pi. XXX. fig. 6, 1871; Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 199, 1873; G. Duuker, 

 Index Moll. Maris Japonici, p. 254, 1883. 



Shell small, almost squ.are, with rounded angles, nearly straight or slightly indented 

 posteriorly, rounded laterally and in front. Upper valve conical, vertex situated at 

 about one third of the length of the valve from the posterior margin ; surface smooth, 

 marked with concentx'ic lines. Lower valve almost flat, attached to marine objects by 

 its exterior surface. In the interior of the upper valve a narrow margin encircles the 

 valve, and close to the posterior margin are two slightly oblique oval-shaped projecting 

 divaricator muscular scars widely separated from one another ; towards the middle of 

 the bottom of the valve two large oblique projecting elevated oval-shaped adductor mus- 

 cular projections arise, gently excavated along their middle ; these scars are so large that 

 they almost divide the valves into two portions, and are separated at the middle of the 

 shell by a blunt ridge, which extends some distance towards the front. In the 

 interior of the lower or attached valve the adductor and divaricator muscular scars 

 occupy a similar position to those in the upper valve, but do not project nearly so 

 much. Colour dirty white. Length and breadth 3| lines. 



Hab. Dredged by A. Adams at Gotto, Japan, in 71 fathoms. 



* Crania rostrata, Sowerby, Thes. Couch, p. ;j(iS, pi. Ixxiii. figs. 12-14, Ib-lU : L. Keevc, Conch. Icon., Monogr. of 

 Cra7ua, pi. i. fig. 3, 1862. 



SECOND SERIES. — ZOOLOGY, VOL, IV. '2('> 



