39 



ON NEORYALIMAX BRASILIENSIS, n.gen., N.sr. (ALLIED TO 

 HYALIMAX), FEOM BRAZIL. 



By De. Heinrich Simroth. 



Read lOth January, 1896. 



PLATE V. 



Not long ago I received for examination, from the Berlin Museum, 

 a well-preserved specimen of a small slug, -wliicli Dr. Von Jhering had 

 found in llio Grande do Sul. It had been registered as a ITyalimax, 

 and outwardly it resembles that genus. Its general appearance agrees 

 with the figure given by Fischer (I); the mantle, however, is more 

 flattened, and some other dilferences of minor importance exist, which 

 j will be discussed later on. 



I Since the genus Hyaliinax is restricted to the Nicobar and Andaman 



I Islands and to Pegu, the discovery of a closely allied form in Brazil 



is of great note, the importance of which is yet further increased by 



the fact that there is a striking deficiency of slugs in the neotropic 



' region. Heynemann (2) enumerates from Mexico, Central America, 



. Columbia, and the West Indies (omitting Liinax and Vaginula) the 



\ genera Tehen)wphorus, Megapelta, Pcltella, and Cryptostracon, and no 



|. other genus from the whole of South America. From the adjacent 



I parts of J^ortli America we have Arion, Ariolimax, Propltysaou, 



' HempliiUia, and Pallifera. The indigenous genera apparently liave 



j but a limited distribution, Without dissection it is impossible for me 



to throw any light upon the mutual relations of these genera, but 



there is no difficulty in eliminating them from the present discussion, 



because those genera living in Brazil which somewhat resemble the 



new slug — i.e. Cry ptostr aeon and PelU'lla — have ribbed jaws. 



The specimen in question, being unitpie, cannot be sacrificed, so 

 the following description of it is necessarily imperfect. 



llie animal is a true slug, i.e. there is no opening in the mantle ; 

 nevertheless, it is not limacoid, for the body is flattened, the foot-sole 

 is too broad, and the mantle too much expanded. Length, 17 mm.; 

 breadth of the foot, 7 mm. The foot-sole is of a pale flesh colour, 

 without grooves. The locomotor disc can only bo distinguished from 

 the sides towards the posterior end. The mantle occupies the full 

 breadth of the animal, and half its length. It is flat on the upper 

 surface, thus corresponding with the shell below. There is no mantle- 

 cap, as in Limax or Avion., the prounnent declivous portion not being 

 broader than the mantle edge of Helix. The skin of the neck is united 

 to the mantle almost immediately behind its anterior margin, and in 

 front of the shell. The mantle has a groove all round the margin, 

 a little deeper in front than behind. The pulmonary aperture is on 

 the right-hand side of the mantle, somewhat behind the middle (PI. V, 

 Fig. 2). Although the mantle margin is thick and fleshy, the shell 



