OCR Text |
Show 1867.] MR. A. ADAMS ON NEW JAPAN SHELLS. 313 direction, obliquely upwards, on the fore part of the body. The tentacles are filiform and very long ; and the eyes, large, black, and conspicuous, are on slight swellings at their outer bases. The front edge of the mantle is extended, and gives the appearance of a large veil over the head. The mantle is not developed, nor does it cover the shell as in some members of the Fissurellidee, and neither the mantle-margin nor anal tube is fringed. The edge of the mantle is furnished with short papillee, four on each side and two behind, which are recurved over the edge of the shell. The anal tube is elongate and cylindrical, and is directed backwards and a little upwards through the foramen in the shell. The foot, large and fleshy, is produced behind, and tapers to a point; it is ovate in outline, and the sides are simple and not furnished with cirri or papillee, as is the case with some other genera of the family. In progression the form of the foot varies considerably, sometimes being greatly dilated at the sides, and at others extended in front and contracted and pointed behind. Hab. Tabu-Sima, Japan : dredged from 25 fathoms of water. There are about a dozen species of this group already described, but the animal has not hitherto been figured. The tentacles are red; the eyes black, with a light areola; the body is light brown, lineated with darker brown. Genus CCELOPOMA, A. Ad. Operculum datum, conicum, concavum, corneum, lamina spirali cornea instructum. Testa subdiscoidea, late umbilicata ; peristomate simplici, superne subangulato. CO3LOPOMA JAPONICUM, A. Ad. (Pl. XIX. figs. 29, 29«.) C. testa turbinato-depressa, striata, castanea; spira vix elata, sutura profunda ; anfractibus 4|, convexis, cylindraceis, ultimo antice subdilatato, descendente; umbilico lato, profundo; apertura perobliqua, vix circulari, peristomate recto, superne subangulato. Diam. maj. 14, min. 11, alt. 6| mill. _ Hab. Tsu-Sima. On dead leaves among stones in shady woods and rocky places. . . . , In this form of Cyclophoridee the peritreme is similar to that o Myxostoma or Cyclotus, being nearly simple and continuous, and without the peculiar notch of Pterocyclos. The operculum, on the other hand, is very similar in form to that of Pterocyclos, being elevated, conical, and hollow; but whereas in Pterocyclos the spiral lamina is calcareous, and stands out horizontally from the margin of the whorls, in Ccelopoma it is horny and closely imbricate. While the animal is on the move, the operculum, which is carried close to the body, is received into the cavity of the wide nmbilicus, and the foot tapers into a point beyond. Ihis is the same mollusk I described in the - Annals for 1861 as a species of Pterocyclos. |