6 AKT. JO. :\r. YOKOYAMA. 



1.5 millim. in length. Our specimens are not unlike P. oahe- 

 shoUianvs Forbes (Echinoderms of the London Clay, Pala3ont. 

 Soc, 1852, p. 35, Woodcut) from the English Eocene, though 

 they are somewhat less sharply pentangular. 



The depth at which the specimens were obtained was 403 feet. 



BRACHIOPODA. 



2- Terebratula miikensis n. sp. 

 PI. III. Figs. 6a, 6b. 



We possess only a single ventral valve firmly attached to a 

 rock. It is moderately large, ovate, longer than wide, with the 

 widest part anterior to the middle of the shell. It is provided 

 witli a broad shallow longitudinal median depression most 

 distinct in its anterior half. The lateral as well as the frontal 

 sutures run almost straight. The beak is moderately produced 

 and incurved, truncated by a comparatively small foramen 

 margined anteriorly by small deltidial plates. The surface is 

 smooth, traversed by lines of growth which are rather coarse in 

 the anterior pait of the shell. The length measures 35 millirn., 

 the breadth 24 millim., and the thickness about 20 millim. 



This species seems to bear a close resemblance to one 

 figured by Davidson in his paper on the " Tertiary Brachiopoda 

 of Belgium " (Geol. Mag., 1874) without a specific name, (pi. 

 VIIT, fig. 9) said to have been found in the Landénien of that 

 country, which corresponds to the lowest portion of the London 

 Basin. 



The specimen was obtained at a depth of 240 feet. 



