6o 



The "Siboga" Expeditioti collected two young and two half-grown shells in a deep-sea 

 trawl at St. 52 (9° 3^4 S., 1 19° 56'.7 E.). I figure one of the shells. 



4. Limopsis belcheri (Adams & Reeve). (Plate II, figs. 9 — 12). 



1850. Pectiinculus Belcheri Adams, A. & Reeve, L., Zoology Voy. "Samarang", p. 76, pi. XXII, 



fig- 5- 

 1858. Limopsis Belcheri Adams, H. & A., Gen. Rec. Moll., II, p. 544. 



Lamy ^) in his revision of the récent species of the genus Limopsis did not deal with 

 L. belcheri in any détail, and only noted that it is probably allied to L. cumingii A. Adams. 

 I hâve examined the type-shell of the species in the British Muséum (Nat. Hist.), London, and 

 hâve no doubt about its being a distinct species. The first point that deserves considération in 

 référence to L. belcheri is that of its habitat. In the original account in the Zoology of the 

 "Samarang" the species was stated to hâve been collected at the Cape of Good Hope at a 

 depth of 120 fathoms. Later Adams ^) in writing of the habitat of Z. abyssicola noted that "the 

 shell figured as F ectunctilus belcheri (Moll. Voy. Sam. pi. 22, f. 5), a much larger and more 

 compressed species, was, I believe, obtained from the Korean Islands". The type-shell bears the 

 label "Sooloo Sea, 40 fathoms, mud". In view of a number of shells collected by the "Siboga" 

 Expédition at St. 95 in the Sulu Sea agreeing with the type shell of L. belcheri^ I am of opinion, 

 that the locality as noted on the type-shell is correct. In view of the meagre description of the 

 species by Adams & Reeve I append a few remarks on the type-shell. 



The species is of a large size, with an oblique ovate shell, rather compressed with acute 

 umbones situated about the middle. The anterior side is shorter than the posterior, it is broadly 

 curved and runs gradually into the evenly curved ventral margin ; the posterior is less arched 

 and appears almost straight. The hinge margin is moderately broad and only slightly arcuate; 

 there are 10 teeth anterior to and 7 posterior to the triangular ligament. The sculpture consists 

 of fine radial and concentric ridges which are covered up by a coarse fibrous epidermis. The 

 inner margin of the shell is finely crenulated. The measurements of the type shell are : — 

 Length 30 mm., height 26 mm., diamëter i i mm. 



Distribution : — The type-shell of this species, as discussed above, probably came from 

 the Sulu Sea. 



The "Siboga" Expédition obtained a number of dead and worn shells from St. 95 

 (Sulu Sea, 5°43'.5N., ii9°4o'E.). 



5. Limopsis datitzenbergi sp. nov. (Plate II, figs. 13, 14). 



The foUowing is a description of this new species : — Shell small, subovate, moderately 

 convex, subequilateral ; umbones not very prominent, acute, curved inwards and backwards, 

 sculpture consisting of strongly raised, concentric ribs which become eut up into minute almost 

 rounded granules by the fine radial riblets; radial riblets more prominent anteriorly and 

 posteriorly ; in front of the ligament are 3 — 4 almost vertical teeth, the innermost of which is 



i) Lamy, E. — Journ. Conchyliol., LX, p. 119 (1912). 

 2) Adams, A. — Proc. Zool. Soc. London, p. 230 (1860). 



