Fossils from the Miura Ft. n insula and its Immediate North. 183 



show a distinct median sinus, a character wanting in the nearly 

 related T. japonic < (Sow.) Davidson (1. c. p. 34, pi. Ill, fig. 7-11). 

 From T. cailleti, our species is distinguished by somewhat finer 

 riblets. The most perfect example which is in our possession meas- 

 ures 15,5 millim. in length, 12 millim. in breadth and 8 millim. 

 in thickners. Another specimen which is smaller measures 11 

 millim. in length 9 millim. in breadth and 5 millim. in thickness. 



Fossil occurrence in Japan. — Miyata Zone (Jinya-ato in 

 Kami-Miyata) ; Kosh il »a zone (Koshiba). 



Fossil occurrence in foreign countries. — English Crag (('oral- 

 line). Scaldisien of Belgium, Pliocene of Italy, Greece, Madeira and 

 the Azores, Miocene of Dax in France and of Turin in Italy. 



Living. — Japan (according to Davidson); Northern Pacific; 

 Northern America; Atlantic; Mediterranean. 



•235. Terebratulina quantoensis, Yokoyama. 

 Pl. XIX. Figs. 19, 20, 21, 22, 23, 24. 



Terebratulina quantoensis Yokoyama, Brach, fr. Neogene of Koshiba, 1. e., p., 2, pl. v, figs. 

 4-9. 



The shell is ovate to pentagonal, somewhat longer than wide, 

 the widest part lying a little posterior to its middle. The valves 

 are unequally convex, the ventral valve being more convex than 

 the dorsal and slightly flattened longitudinally along its median 

 line. The foramen is large, oblique, incomplete, margined anteri- 

 orly by the beak of the dorsal valve and two small discontinuous 

 deltidial plates. The sculpture consists of numerous radiating 

 riblets which augment in number by bifurcation and also by the 

 interpolation of shorter riblets between the longer ones. Incre- 

 mental lines distinct. 



On account of the difficulty of bringing the loop into view, the 

 generic name is only provisional. 



There is a great variation in the shape of the shell, as is com- 

 mon in this group of animals. Taking its length as 10, the breadth 

 varies between 8.2 and 8.6, while its thickness is between 4.4 and 

 5. The largest example measures about 35 millim. in length. 



