244 MESSES. COLLINGB AND GODWUf-AFSTEN" OX [Mar. 19, 



2. The form of the mantle-lobes indicates a relationship to 



some form in which the left shell-lobe has become largely 

 developed along the whole mantle-edge together with the 

 right, as displayed in Girasia and Macrochlamtjs, but in 

 which last-named the development of the shell-lobes has 

 been more equal and commenced at t\AO distinct points. 



3. The position and form of the caudal mucous gland. 



4. The straight jaw. 



5. The broad lingual ribbon and great number of teeth of a very 



different form. 



While not inclined to attach any great importance to these two 

 last-mentioned characters, we consider them of sufficient value to 

 place this mollusc in the subfamily Durgellince. 



On compai'ing Damayantia smitlii with Tennentia philipinnensis, 

 Semper (6), we iind it differs in the presence of the coil in the 

 amatorial organ and in the form of the central tooth. The 

 separation between vagina and free-oviduct also differs. Tennentia^ 

 is probably synonymous with Issel's genus. It was founded by 

 Humbert on a species from Ceylon, viz. *. thivaitesi, which is 

 only a synonym of Manella dussumieri, Gray, said to be from 

 Mahe in the Seychelles. The genus Dekhania, Godwin-Austen, 

 type beddomei, G.-A., is also the same as Mariella and must be 

 suppressed. 



Issel (4) in 1874 figured and described three species of slugs 

 from Sarawak, one of which, dilecta, is the type of a new genus 

 founded by him, viz. Damayantia (4. figs. 4 & 6), on external 

 characters only. This is shown to have exactly the same peculiar 

 concentric markings on the mantle as Damayantia smitJii, and in 

 spite of the statement of Issel that there is no shell, we believe 

 them to belong to the same genus. These very thin membra- 

 naceous shells may easily escape notice ; and, further, in all the 

 species from the Indian region, to which one of us (H. H. G.-A.) 

 has devoted special attention, a shell is always present, however 

 small and membranaceous in size and texture it may be reduced to. 



The two other species recorded by Issel are D. dorice (pi. iv. 

 figs. 7 & 8) and D. beccarii (pi. iv. figs.' 9, 10, & 11). The latter has 

 a thin immature shell (fig. 10), but the jaw figured (fig. 11) has a 

 strong central projection. Issel has placed them in the genus 

 ParmaTrion. 



MiCBOPAEMAEiOK, Simroth, 1893. 



III. MiCBOPABMAEION POLLONEEAI, n. Sp. 



Shell (fig. 13) flat and expanded, auriculate, the apex white, 



shelly, the rest olive-green, membranaceous yet solid ; two whorls. 



Major diameter 16 millim., minor diameter 10 millim. 



The posterior side of the shell is very thin aud diaphanous and 



falls around the edge of the shell, covering the side of the visceral 



1 mass. In this respect it recalls the shell of the South Indian 



A-/ Africarion pallets, " Morel.," G.-A. ; but here the similarity ceases, 



