448 MR. W. T. BLANFORD ON OPISTHOSTOMA. [Nov. 22, 



Southern India in 1857. The rediscovery of the genus is none the 

 less fortunate, that specimens of the original species are so exces- 

 sively rare that it has heen impossible to distribute them so as to 

 make the form known in Europe. I have on two separate occasions, 

 in 1859 and 1864, searched the neighbourhood of Pykara, on the 

 Nilgiris, without success, and, owing to an unfortunate accident, 

 by which most of the original specimens were lost, I believe that 

 but two now remain, one of which is in my own collection, and an- 

 other in Mr. Benson's. Several specimens of the new species have, 

 fortunately, been obtained ; and it is to be hoped that the number 

 may be increased, as the locality is easy of access. 



The new form is a very near ally of O. nilgiricum*, H. Blanf. 

 (PL XXXVIII. fig. 13), but still readily distinguished by several not 

 unimportant characters. Specimens have, fortunately, been obtained 

 living, enabling me to complete the cbaracters of the genus, and to 

 confirm the opinion expressed by my brother, in our joint paper, of 

 its being an operculated form. Although 1 bave not succeeded in 

 examining the animal so closely as 1 could have wished, I have been 

 able to note the form of the tentacles, with the position of the eyes, 

 and to see the operculum. All tend, I think, to bear out the views 

 I expressed, in 1864f, as to the affinities of the genus. 



Before proceeding to any further remarks, it will be well to de- 

 scribe the new species, and to give the generic characters as now 

 ascertained. 



Opisthostoma, H. Blanf. 



Testa anguste umbilicata, umbilico interdum ah anfractu ultimo 

 obtecto, irregulariter pupceformis, costulata, anfractibus api- 

 calibus deflexis, anfr. ultimo constricto ibidem angulo acuto 

 deflexo, retro curvato, denique sinistrorsum ascendente. Aper- 

 tura retrorsa, circidaris vel subcircularis. Operculum tenue, 

 corneum, concentrice paucispirale, profunde retractum. Ani- 

 mal tentaculis brevibus, cylindricis, obtusis, oculis ad basin 

 externum tentaculorum sessilibus, lateraliter positis sed Cyclo- 

 phoridarum altioribus. Pes brevis. Proboscis brevissima. 



Opisthostoma fairbanki, n. sp. (PI. XXXVIII. fig. 14.) 

 Testa irregulariter ovata, albida, confertim costulata, lineis im- 

 p>ressis spiralibus minutis, vix sub lente conspicuis, seepe obso- 

 letis, inter costulas signata. Spira breviter subcylindrica, 

 apice perobtuso, sutura profunda. Anfr. 5, rotundati, duo 

 apicales parum exserti, ex axi deviantes, tertius multo major, 

 quartus maximus, quintus brevissime constrictus, ad stricturam 

 angulo acuto versus umbilicum deflexus, in figuram literce S 

 curvatus, umbilicum omnino tegens, denique sinistrorsum ascen- 

 dens, anfr actus penultimus undique junctus. Aperturu postica, 



* Described and figured in the 'Journal of the Asiatic Society of Bengal,' 

 vol. xxix. p. 121, 1860. The figures are very good, 

 t Ann. and Mag. Nat. Hist. ser. 3. vol. xiii. p. 444. 



