48 



ON THE GENUS EURTSTOMA OF ALBERS (TYPE VITTATA, 

 MiJLLER), ITS ANATOMY AND REFERENCE TO OTHER 

 INDIAN SPECIES. 



By Lieut. -Colonel H. H. Godwin-Austen, F.R.S. 



Mead 8th January, 1904. 



PLATE IV. 



Last July I received from Dr. W. T. Blanford some specimens of this 

 species preserved in alcohol, whicli had been obtained in the Tinnevelly 

 iSisLrict, Madras, through Dr. Thurston, of the Madras Museum, to 

 whom our thanks are once more due for supplying us with the 

 animals of several interesting land-sliells. This species {vittata) is 

 of interest as it was made the type of a genus by Dr. J. C. Albers 

 under the title of Eurystoma,^ and is the first of the two species that 

 author included in it. The second species, H. dejlexa, Pfr. [exdeflexa 

 of Pilsbry), from Cuba, is placed by the latter author in Eurycampta. 



The genus was founded on shell character alone, and is thus 

 described from a Ceylon example: — "Testa umbilicata, depresso- 

 globosa, snlida, spira brevis, obtusa ; anfractus 5 planulati, ultimus 

 basi inflatus, antice descendens ; apertura lunari-oyata ; peristoma 

 expansum, marginibus conniventibus, callo junctis, columellari 

 umbilicum semitegente." 



Conchologically the type shell has been associated by early writers 

 with Helix [Arianta) arbtistorum; Adams places it in Macrocyclis, 

 a South American genus ; G. Nevill * has it in Planispira, and records 

 a single specimen from Java as coming fi'om Ferdinand Stoliczka's 

 collection, but extension to this island would be remarkable, and its 

 occurrence there requires verification. 



Bescrvption of Animal. — The visceral sac (Fig. 3) has no markings of 

 any kind, being a rich ochre coloi^r throughout, more intense on the 

 apex, and near the mantle- zone it is burnt sienna colour. From the 

 appearance of the foot in spirit it would appear to be broad and 

 rounded at the posterior end in the living animal. There is no 

 peripodial line ; the surface of the sides is smooth, broken up by close- 

 set radiating grooves. The main divisions of these are well seen on 

 the sole of the foot, gradually fining out towards a plain central area. 

 This last becomes more pronounced anteriorly, and nearer the head 

 it is strongly divided down the middle, and is further split up and 

 finely streaked longitudinally; the muscles of the foot apparently have 

 this arrangement, which is intensified by contraction in the spirit. 

 A central and the side areas of the sole of the foot are a conspicuous 

 character (Fig. 2). The mantle-edge is quite straight and simple. The 



> "Die Heliceen," 1850, p. l'2(i. 

 2 Plaudlist, p. 76. 



