118 PROCEEDINGS OF THE ACADEMY OF [Feb., 



This species is allied to D. rectius Cpr. and cequatorium Pils. and Shp., 

 but differs from both in its distinct though extremely minute annular 

 sculpture. It is a typical Rhabdus, and the first to be found in Japan- 

 ese waters. 



Siliqua intuspurpurea n- sp. PI. V, figs. 82, 33. 



Shell regularly oblong, compressed, entirely covered with a glossy 

 cuticle, green-yellow with darker olive concentric streaks, becoming 

 purple toward the beaks, which, however, are white or whitish. The 

 surface is lightly marked with growth-lines, and has a group of indis- 

 tinct rays, composed of short, minute wrinkles in the direction of 

 growth-lines, in the middle; and the dorsal surface posterior to the 

 beaks is densely sculptured with minute raised radial lines. Upper 

 and lower margins about equally convex ; posterior end slightly trun- 

 cate obliquely; anterior end rounded. Beaks at the anterior three- 

 tenths of the length. Ligament short, black-brown, and prominent. 

 Interior purple, the rib strong, straight and nearly vertical, whitish- 

 purple. Pallial sinus extending anteriorly two-fifths the total length, 

 its lower margin coalescent with the pallial line. Two cardinal teeth 

 in each valve. 



Length 41, alt. 21, diam. 9 mm. 



Akkeshi, Kushiro (Hokkaido). Types No. 88,295, A. N. S. P., from 

 No. 1,617 of Mr. Hirase's collection. 



Related to the Calif ornian S. lucida Conr., but that is a narrower 

 species. The internal rib shows as an indistinct whitish ray outside. 



Maorocallista ohishimaua n. sp. 



The shell is oval, rather solid, white under a glossy cuticle. Drab 

 with lighter concentric streaks, becoming pale yellow near the base 

 and ends, and rather indistinctly marked with drab rays. Surface 

 everywhere closely but irregularly concentrically plicate-striate. 

 Under a strong lens a dense microscopic sculpture of papillae and lines 

 parallel to growth-lines is seen to cover the riblcts and intervals. 

 The dorsal and basal margins are about equally convex, the dorsal 

 margin anterior to the beaks is nearly straight, the anterior end being 

 rather narrowly rounded. The lunule is rather narrow, flat, bounded 

 by a slightly impressed line. The interior is pure white, dull; the pal- 

 lial sinus rather short and rounded. Teeth are rather slender. ]\Iar- 

 gins of the valves are smooth and partly covered by the inflexed 

 cuticle. 



Length 64.5, alt. 48, diam. 28.5 mm. 



Shikotan, Chishima (Kuril Is.). Type No. 88,301, A. N. S. P., from 

 No. 1,615 of Mr. Hirase's collection. 



