560 PROCEEDINGS OF THE ACADEMY OF [July, 



and vertical in the middle, somewhat irregular there and anteriorly, 

 but posteriorly they become coarse and very oblique, and strongly 

 crenulate on the upper edges. The count of teeth in three shells is 

 as follows, the anterior end preceding : 



23, 17 = 40 teeth; length of shell 44 mm. 



18, 26 = 44 teeth; length of shell 44 mm. 



15, 30 = 45 teeth; length of shell 53 mm. 



The interior is dirty white, sometimes with brown stains, the edges 

 crenulate and brown. 



Length 53, alt. 24, diam. 26 mm. 



Length 44, alt. 21, diam. 23 mm. 



Co-types No. 78,750, A. N. S. P., from the east coast of Japan, col- 

 lected by Miss Anna C. Hartshorne (fig. 17), and No. 58,082, received 

 in a lot of shells from northern Japan, probably Yesso, but the exact 

 locality is unknown. 



I take these shells to belong to the species described by Kobelt in 

 his excellent monograph cited above, and referred by him with great 

 doubt, and on the authority of Mr. E. A. Smith, to A. ocellata Reeve, 

 described from Singapore. Having before me topotypes of A. ocellata, 

 as well as several Japanese specimens which agree with them, I am 

 compelled to regard the two species as entirely distinct, and not even 

 closely related, although they agree in general shape. The ligament- 

 area in A. ocellata is smooth, scored by only a few, usualh' imperfect 

 ligament grooves, there being a large oblique triangle posteriorly and 

 an erect triangle between the beaks free from them. The two oblique 

 triangles marked by grooves are usually covered with a smooth yellow 

 (or in some Japanese shells, blackish) cuticle, while the rest of the 

 area is whitish. This is well shown in the dorsal aspect of a specimen 

 of A. ocellata from the province of Suruga (No. 71,041, A. N. S. P.), 

 drawn in fig. 21 of pi. XL. 



Area ocellata does not attain nearly the size of A. hobeltiana, an adult 

 Singapore shell measuring, length 26, alt. 12.5, diam. 13 mm. The 

 Japanese specimens with unworn surface are somewhat more regular 

 in growth than those from Singapore, and have a very narrow ven- 

 tral gape. One measures, length 20.5, alt. 11.6, diam. 10.6 mm. The 

 diagonal keel is very acute. 



Reference to Plates XXXIX-XLI. 



Plate XXXIX, Figs. 1, 2, 3. — Mactra carneoplda Pils. 

 Figs. 4, 5, 6. — Spisula bernardi Pils. 

 Figs. 7. 8, 9.—Pitar sulfurea Pils. 

 Figs. 10, 11. — Cytherea crispata amida Pils. 



