EEPOET ON THE BRACHIOPODA. 55 



keeled. Beak slightly incurved, with a rather large incomplete foramen and two small 

 lateral deltidial plates ; beak ridges sharply defined, leaving a flattened area between them 

 and the hinge-line. Surface of valves covered with numerous small radiating ribs, which 

 increase in number at variable distances from the beaks from the bifurcation of many of the 

 ribs and the interpolation of shorter ones. Some of the ribs are likewise shorter than others. 

 The valves are also crossed at variable intervals by fine concentric lines of growth. In the 

 interior of dorsal valve a forked process for the support of the brachial appendages rises 

 nearly centrically from the septum, its upper extremities being branched. The brachial 

 appendages are small and do not occupy a space larger than about half the length of the 

 valve, central spiral lobe very small. Length of a large example 15, width 17, depth 6 mm. 

 Habitat. — A small number of very fine examples of this species were dredged by the 

 Challenger Expedition, off the Cape of Good Hope, associated \wth Terehratula vitrea, var. 

 minor, and Terehratulinacaput-serpentis, var. septentrionalis, at Station 142, lat. 35° 4' S., 

 long. 18° 37' E., on December 18, 1873. Depth, 150 fathoms. Bottom temperature, 

 8° "3 C. Sea bottom, sand. It has also been dredged near Natal. 



Observations. — This is a well-known South African species. The so-called Kraussina 

 cognata of Chemnitz, will, I believe, very probably turn out to be a large malformed 

 example of the shell under description. My opinion is shared by Mr DaU. Kraussina 

 deshayesi is, as was justly remarked both by Reeve and DaU, closely allied to Kraussina 

 pisum, but it is a more triangular form, and painted -with deep crimson rays. It may, 

 however, be the same as Kraussina capensis of Adams and Reeve. I have observed the 

 row of spine-like projections round the inner margin Kraussina cognata, a character 

 apparently common to several, if not all, the species of the genus. I have noticed them 

 in Kraussina rubra of Pallas, and also in Kraussina lamarckiana. Kraussina lamarchi- 

 ana is a much smaller species than Kraussina pisum, and its ribs are comparatively 

 coarser. Krauss gave a good description and illustration of the forked process in 1848. 



Platydia, Costa. 



Platydia anomioides, Scacchi, sp. (PL IV. figs. 10, 11). 



Terehratula appressa, Forbes, Britisli Association Eeport, p. 193, 1843. Rep. !Moll. JEgean Sea, p. 



141, 1844. 

 Orthis anomioides, Scacchi, Philippi, Famia MoUuscoriim Regni Utriusque SiciliiK, tab. xvii., fig. 9, 1 844. 

 Platydia anomioides, Costa, Fauna del regno di Napoli, p. 48, pi. iii. his, fig. 6, 1843. 

 Mornsia anomioides, Dav., Ann. and Mag. of Nat. Hist., p. 371, 1852, and S. P. Woodward, Manual, 



p. 218, fig. 119, 1856. Eeeve, Mon. of Tprehratula, Conch. Icon., pi. x. fig. 40, 1861. 

 Platydin anomioides, DaU., Cat. Eecent Brach., Proc. Phil. Acad. Nat. Sciences, p. 192, 1873. 



Shell small, transversely oval or nearly cu'cular, semitransparent, yellowish-white, 

 conspicuously perforated by minute canals, foramen large, encroaching equally on Ijoth 

 valves. Dorsal valve nearly flat, and mesially depressed ; umbo notched liy a semi- 



