Fossils from the Miura Peninsula lui<1 its [mmediate N"orth. \Ar. 



numerous, low, wavy, concentric laminae, more wavy in the 



anterior than, in the posterior half; and these waves are so 

 arranged as to cause their crests to form radiating ribs which 

 become fainter towards the posterior, getting quite obsolete near 

 the posterior end of the surface. In some specimens the lamina' 

 in the posterior part are cut up into many small parts or tubercles 

 which are again aiTanged in a radial direction. 



In none of the several specimens at hand is the dorsal shield 

 preserved. The largest one measures 30 millim. in length and 1 1 

 millim. in height. 



Fossil occurrence. — Yokosuka Zone (Otsu and Yokosuka). 

 Upper Musasbino of Shimosa. 



Living. — Western Japan; Philippines. 



Genus .Fouannelia. C. des Moulins. 



125. Jouannetia japonica, Yokoyama. 



Pl. VII. Fig. 1. 



Shell small, thin, fragile, globose, widely gaping in front, 

 with the anterior end bluntly pointed and smooth, and the 

 posterior end rounded. Surface divided into two parts by a deep 

 groove running from beak to antero-ventral angle, whence the 

 margin which is crenate ascends obliquely upward anteriorly. 

 The sculpture consists of distant concentric laminae which in the 

 anterior portion are wavy, the crests of the waves forming about 

 eight radiating ribs whose interspaces are unequal, being broader 

 in the anterior portion. Accessory plates not preserved. Height 

 6 millim.. length about 7 millim. Rare. 



Quoy and Gaimard described an allied species from the 

 Philippines under the name of Photas globulosa (Voy. Astrolabe, 

 III, p. 549, pi. 83, tigs. 16-19) in which, however, the anterior 

 end is serrate, and there is a radiating row of angular points in 

 the middle of the posterior half of the surface. 



Another allied species is living in the Pay of Sagami. It is 

 still undescrihed. but is very close to the fossil form, the chief 



