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Show 448 REV. A. H. COOKE ON [May 17, in the 'Reisen'1 is admitted, even by its author, to be hardly satisfactory. But there is practically a'general agreement between Semper and Pfeiffer 2, since both agree in the limitations represented by about 10 of the subgenera, the chief points of difference arising with regard to the respective limits of Calocochlea and Helicostyla, of Helicobulimus and Orthostylus, of Orthostylus and Canistrum, and the restriction of Canistrum proper. The distinction, if any, between some of these groups is, unless and until some definite anatomical difference is established, at best arbitrary. After careful consideration I have decided to abolish Helicobulimus altogether, merging it in Orthostylus. The species are in any case few (Pfeiffer enumerates only 5, and one of these, grandis, Pfr., is better classified as Calocochlea), and different authorities are much at issue with regard to referring specific forms to one group or the other. This seems sufficient reason for refusing to draw a line between them. With regard to Orthostylus and Canistrum (Pfr.), there is a very long series of forms ultimately connecting such typical Orthostyli as, e. g., daphnis, Brod., and rufoyaster, Fer., with elongated shells like camelopardalis, Brod., and nympha, Pfr. But the extremes are so wide apart that it m a y be worth while to try to separate them, and I do so by regarding pictor, Brod., as a sort of border-line form, removing it from Orthostylus, and considering it and all the more elongated forms as belonging to a separate group (Hypselostyla, Mts.). This group is practically identical with Semper's ' Elongatee,' for there is strong ground for restricting, with Semper, the group Canistrum to a peculiar section of shells3, the type of which is ovoidea, L a m . ( = luzonica, M6rch, = euryzona, Pfr.). The localities given in each case have been most carefully considered, and no species has been taken into account whose locality is not regarded as authoritative. Thus the locality ' Philippines,' so often given by the older writers, is useless for the present purpose, and species not further localized (a considerable number) have been neglected altogether. Recent investigation has been more exact in its record of localities, and in the present paper 180 species in all are brought to account. Further, it has been found necessary to neglect Cuming's authority as establishing any locality whatsoever. Those familiar with his method of preserving localities will understand this, and it need only be added that Semper and von Mollendorff are continually at issue with him. He may be taken as confirming, but 1 (1) Corasia, (2) Callicochlias, (3) Globosce, (4) Hypomelance, (5) Cinerea, (6) Axina, (7) Helicostyla, (8) Orustia, (9) Sphcericce, (10) Cochlodryas, (11) Orthostylus, (12) Elongatee, (13) Phengus, (14) Eudoxus, (15) Canistrum, (16) Pro-chilus, (17) Chrysallis, (18) Phainicobius. 2 Nomencl. Hel. Viv. pp. 202-212. Von Mollendorffs paper on the sub-generic classification of Cochlostylce (Jahrb. deutsch. mal. Gesell. xii. p. 72) places the divergence at its maximum. 3 Semper,' Eeisen,' II. iii. p. 219, places in this section the following species :- stabilis, Sby., euryzona, Sby., ovoidea, Lam., belcheri, Pfr., balanoides, Jon., breviculus, Pfr., cinerosa, Pfr., dilatata, Pfr. I should agree with him with regard to the first five; cinerosa is probably a var. of satyrus, Brod., which is a Hypselostyla; the remaining two appear doubtful. |
