OCR Text |
Show 1891.] GEOGRAPHICAL DISTRIBUTION OF SLUGS. 225 Indian region1. Mariaella, a very distinct genus, has almost identical forms in S. India, Ceylon, and the Seychelles. Parmacochlea has a single species from the northern extremity of Queensland, but is represented in the Indian region by a subgenus Pseudaustenia (nov. nom.) of Lbycus, the type of which is the Africarion ater of Godwin-Austen. Austenia is a genus of the Indian region, with some very different species, which will probably form new subgenera. Helicarion is very numerous in species, about 101 being known. The genus is quoted from Africa, the Indian, Chinese, and Malay regions, Australia, &c. It is very noteworthy, however, that it seems to be absent in N e w Zealand, the H. dimidiatus of that island being an Otoconcha. It is found, nevertheless, in the Auckland Is. (H. zebra, Le Guill.), Lord Howe's I. (H. hilli, Cox), and N e w Caledonia (H. keppelli, Pfr.). It is best developed in Australia (18 species) and the Philippines (17 species). When the animals are fully known, the genus will doubtless have to be subdivided. Such species as H. cumingii, Beck, and H. bocki, Smith, might be separated from Helicarion by their shells alone, at least subgenerically. H.vitrinina and H. ramsayi of Liardet, from the Fiji Is., probably represent a single species showing colour-variation of the animal. TESTACELLID^E. Testacella and Daudebardia are genera belonging to the European, or, more precisely, Western Palaearctic, region, each with a fair number of species. These genera have also been reported from New Zealand, but probably the species referred to by Hutton (Trans. N. Z. Inst. 1883) belong to some other genus. Chlamydephorus is a distinct and peculiar genus from South Africa, with one species. Selenochlamys, Bttg., founded on a species from Transcaucasia, is allied to Daudebardia, but has no shell. SELENITID^E.-Trigonochlamince. A family allied to Testacellidce, but possessing a jaw. The present subfamily includes Trigonochlamys and Pseudomilax from the Caucasian region, and Plutonia from the Azores, the latter monotypic2. Cystopeltince3. Contains only the remarkable genus Cystopelta of Tate, founded on a single species, C. petterdi, found in Tasmania. 1 The group of G. crocea, G.-A., although true Girasia, shows a resemblance to Mariaella in some of its characters. The species which I described as Girasia depressa I now consider to be a variety or subspecies of G. crocea. 2 A most important work by Dr. Simroth on the Portuguese, Azores, and other Slugs has just appeared (Nova Act. Acad. Gees. Leop.-Car. 1891), containing a detailed account of Plutonia. 3 Mr. Hedley has lately published a very interesting paper on Cystopelta in Proc. Linn. Soc. N. S. W . 1890, p. 44. It would seem that this subfamily is intermediate between Selenitidce and Helicarionince. PROC. ZOOL. Soc-1891, No. XV. 15 |