OCR Text |
Show ^SO.] THE GENUS GIRASIA. 291 3. The capreolus apparently does not exist in some Helices; but as it is not always to be detected in Helix aspersa, these require more careful examination. 4. The capreolus serves to aid in the intromission of the seminal fluid, or rather the saving of it, and renders copulation more certain and intimate. Lister considered that the spinules of the capreolus retained the body in the female organ. The more we know of the species of Indian Mollusca which have hitherto been placed in the genus H E L I C A R I O N of Ferussac (Tabl. Syst. 1821), of which a form, H. cuvieri, Fer., was the type (from Australia), the more certain it is that few of the Indian forms, if any, can be retained in it. Of these, two or three are so very distinct they may safely be separated and also described in more detail. Nothing is more satisfactory than to get hold of a type specimen of a genus ; and acting on a note from m y friend Mr. Geoffrey Nevill, and with the kind aid of Mr. Edgar Smith, I have been able to find and examine the type of Dr. J. E. Gray's genus GIRASIA, represented by a single specimen in spirit, which was collected by Sir Joseph Hooker in tbe Khasi Hills. It proves to be m y Helicarion (Hoplitesl) theobaldi, described in the P. Z. S. 1872, p". 517. The subgenus Hoplites was proposed for these Khasi-Hill slugs by Mr. Theobald in the J. A. S. B. 1864, p. 244. No description cf the genus or species is given, save that it was 2 inches long, from Teria Chat, and was probably m y H. theobaldi, I. c. p. 517. This group I now propose to start from, and take up first. GIRASIA, J. E. Gray, Cat. Pulm. Brit. Mas. p. 61 (March 1855). The original description (which I give below) is imperfect; no mention is made of the mucous gland, save in the synopsis of the generic section in which it is placed:-" Body united to the back of the foot, only separated by the convex hinder edges. Shell partly exposed, ovate, expanded, with a solid apex. Back of the neck (under the collar) with three grooves, the central groove between the tentacles double-edged ; the lateral one single, bent down on each side to the sides of the head at the back of the lower tentacles1; the head is only partly retractile, so that the base of the upper tentacles, which are completely retracted, are exposed on the top of the head like two perforations2; the aperture of the generative organs is rather behind the base of the right tentacle. The hinder part of the body attached to the back of the foot nearly to its hinder end, which is separated from the deep concavity on the back of the foot by a deep lunate cross groove. In all these particulars the animal exactly agrees with the Portuguese species of Brusia"3. Type hookcri, Gray. Khasi Hills. These species are added :- Girasial rutellum, Hutton. Kandahar, Kabul. Evidently a Parmacella. Girasia extranea, Fer. Habitat? (Hist. Moll. ii. 96.) " Shell a thin horny pellicle, without any appearance of a spire." 1 This sentence is not very clear or accurate. 2 This is merely the description of the state of the spirit-specimen with the eye-tentacles inverted as usual. 3 Then why was it separated ? |