239 



from Cebu received from the author, though it is slightly smaller than the latter; this may 

 depend on age, but the general aspect and the particulars of the suture are the same. 



3. Mucronalia eburnea Deshayes. 



Deshayes. Moll, du Reunion, p. 57, PL 7, fig. 25. 

 Tryon. Man. of Conch. Vol. VIII, p. 290, PL 71, fig. 43. 



KUKENTHAL. Abh. Senckenb. Gesellsch. 1898, p. i, Tf. I, fig. 2, 3; Tf. 3, fig. 14. 

 ScHEPMAN, in Schepman & Nierstrasz, Parasit. Prosobranch. d. Siboga-Expedition, Leiden, 

 1909, p. 3. 



Stat. 254. 5°40'S., 132° 26' E. Arafura Sea. 310 M. i Spec, on Ophiothrix deposita YLoehler. 



Unfortunately the only specimen was broken, consequently the identification slightly 

 doubtful, however the upper whorls and texture of shell agree with the numerous specimens 

 I have seen. Deshayes and Tryon (1. c.) have described the species as a SHlifei^. The Siboga- 

 specimen is provided with an operculum. 



4. Mucronalia Mittrei Petit. 



Petit. Journ. de Conch. Vol. II, 185 1, p. 27, PL 2, fig. 8, 9. 

 Tryon. Man. of Conch. Vol. VIII, p. 290, PL 71, fig. 42. 



Schepman, in Schepman & Nierstrasz. Parasit. Prosobranch. d. Siboga-Expedition, Leiden, 

 1909, p. 3. 



Stat. 3 12. Saleh-bay, North coast of Sumbawa. 274 M. i Spec, on Ophiothrix crassispina Koehler. 



By its shape, especially by that of the penultimate whorl, which is uncommonly developed, 

 I cannot distinguish the shell from the species described by Petit as Stylifer Mittrei^ only the 

 Siboga-specimen is much smaller. Petit had only one specimen, without exact indication of 

 locality, and he did not know if it were a parasite ; probably the operculum was wanting, at 

 least Petit does not mention it. With a view on the preceding species it is not strange that 

 this species should be referred to the genus Mucronalia^ on account of the operculum in the 

 Siboga-specimen. Moreover its other conchological characters, sufficiently agree with those of 

 the species dealed with sub 2 and 3, to unite them in the same group. It may be even the 

 question, if after all so many species will stand, when more materials will have been collected. 

 Length of shell 6 Mill, breadth 4 Mill. 



5. Mucronalia parva Schepman. PL XVll, fig. i. 



Schepman, in Schepman & Nierstrasz. Parasit. Prosobranch. d. Siboga-Expedition, Leiden, 

 1909, p. 4. 



Stat. 312. Saleh-bay, North coast of Sumbawa. 274 M. 3 Spec, with the preceding -species. 



Shell small, elongated-oval, imperforate, white, smooth ; whorls about 6 of which the 

 two apical ones are mucronate, the other whorls are broader, strongly convex, with a deep 

 suture, last whorl less convex. Aperture ovate, with an acute angle above, right margin thin, 

 considerably flexuous, columella arched; a thin layer of enamel on the body whorl. Operculum 

 thin, horny. 



