97 



2. Pectinodonta alta n. sp. PL II, fig. 9. 



Stat. 59. Western entrance Samau-strait. 390 M. Coarse coralsand with small stones, i Spec. 



Shell rounded-ovate, elevated, yellowish-white, solid, anterior slope verj? short, slightly 

 convex, posterior slope very convex, side slopes moderately convex, apex rather blunt, slightly 

 eroded, consequently without sculpture, placed of about Y^ of the total length. Sculpture consisting 

 of rather flat, concentric lirae, which are considerably broader than the interstices, which on 

 some parts have the character of mere striae. They are crossed by radiating striae, which are 

 however rather obscure, probably on 'account of the somewhat worn state of the shell. Margin 

 rather thick with the sides raised, though less than in the preceding species. Inside smooth, 

 yellowish, with a large white central area. 



Long. 87,, lat. 77^, alt. 5 Mill. 



Differing from the known species by the more anterior position of the apex, the smoother 

 sculpture, the height of the shell etc. I have located it in the genus Pectinodoiita^ on account 

 of the same considerations as for the former species, as far as concerns the shell, but I must 

 admit, that with such limpet-like species, certainty is only to be obtained by anatomical characters. 



3. Pectinodonta sp. PI. VIII, fig. 13. 



Stat. 297. io°39'S., I23°40'E. 520 M. Soft, grey mud. 15 Spec. 



The specimens collected at Stat. 297 are very small, the largest being about 27^ Mill, 

 in length, nearly 2 Mill, in breadth, alt. Ya Mill. They are oblong-ovate, much depressed, white, 

 smooth to the naked eye or under a weak lens. Under a stronger lens they are concentrically 

 striated and have a subcentral rounded nucleus, under the microscope they show fine hairlines, 

 radiating from the nucleus and varying in length, but always short. They resemble much the 

 apex of P. orientalis, but it is impossible to make out if they are identical, they seem to be 

 more elongate. As the nucleus of P. orientalis was wanting, no comparison can be made. The 

 shape of the head of the animal is very similar. The radula has given an imperfect result, the 

 cusps being loosened by the action of caustic potash, but the isolated cusps are similar in general 

 appearance to those of P. arcuata Dall ("Blake" Gastrop. pi. 35, fig. 3) they have however 

 only 5 denticles at their proximal margin, whereas in P. arcitata they are much more numerous 

 (11); this may depend partly on age, partly on specific difference. Though isolated, some of 

 the pairs of cusps had their natural position, as shown in my figure. 



Fam. Patellidae Guilding. 

 Patella Linne. 

 I. Patella fSmtellastra) stellaeformis Reeve. 



Reeve. Conch. Syst. Vol. II, p. 15, PL 136, fig. 3. 



Conch. Ic. Vol. VIII, Patella, fig. 48 [pentagona). 



PiLSBRY. Man. of Conch. Vol. XIII, p. 98, PL 17, figs. 25—27; PI. 61, figs. 62—65. 



97 



SIBOGA-EXPEDITIE XLIX'a. '3 



