114 PROCEEDINGS OF THE ACADEMY OF [Feb., 



identified guamensis with a shell of which Trochus callosus Koch and 

 Rotella montrouzieri Souv. are varietal forms. No form of this type 

 which I have encountered agrees fully with Quoy's figures and de- 

 scription; and it is not impossible that the real guamensis yet remains 

 unidentified, in which case Ethalia vwntrouzieri will become the senior 

 name for the guamensis of most authors. 



Ethalia guamensis sanguinea n. subsp. Fl. IV, figs. 21, 22. 



Trochuft callosufi Koch, in Philippi, Abhld.. I, PL 4, fig. 2. Philippi in Conch. 

 Cabinet, Trochus, PL 35, fip;. 7 (copied in Man. Conch., XI, PL 57, figs. 

 41, 42). Not T. callosus GmeL 



Shell imperforate, low-conoidal above, convex beneath; glossy and 

 smooth except for fine growth-lines and almost obsolete spirals. White, 

 copiously marbled with purple-brown and pinkisli above, with some 

 opaque white spots, and a few indistinct articulated spiral lines; the 

 base white, with a pink central area. Whorls 5h, convex, the last wide, 

 narrowly rounded at the periphery. Aperture oblique, ovate, the lip 

 thin and simple, calloused near the columellar insertion, the umbilicus 

 wholly filled by a red callous pad, roughened by several irregular vein- 

 like grooves. 



Alt. 10, diam. 15 mm. 



Yakujima, Osumi. Types No. 88,312, A. N. S. P., from No. 1,458 

 of Mr. Hirase's collection. 



This form differs from E. g. selenomphala by having the umbilicus 

 wholly filled, both in half -grown and adult shells, by the roseate 

 callous pad, as in Helicina or Umbonium. The general shape is not 

 unlike, except that the spire is more regularly low-conic in E. g. san- 

 guinea. Moreover, the upper surface is more coarsely maculate, and 

 the base is white except near the central pad. 



Probably ''Trochus callosus Koch" of Fischer {Iconogr. Coq. Viv., 

 PI. 115, fig. 3) should stand as another subspecies of E. guamensis. 

 Rotella montrouzieri Souv. will be still another subspecies. 



Ithalia guamensis selenomphala n. subsp. PI. IV, figs. 27, 28. , 



Shell depressed, biconvex, glossy and smooth except for fine growth- 

 lines and almost obsolete spiral lines on the last Avhorl. It is white, 

 the upper surface sparsely marbled with purplish and pink, suffused 

 with pink on the spire, and encircled with numerous fine lines articu- 

 lated white and pink or brown. Base white, with a few pink spots. 

 The upper surface is convex, the inner w'horls only projecting in an 

 acute little cone. Whorls 6^, convex, parted by a well-impressed 

 suture, the last whorl very wide, narrowly rounded, almost subangular 

 peripherally. The base is convex. The aperture is very oblique, 



