110 LAND AND FRESHWATER 



MiCROCYSXINA. 



{Continued from Vol. I. p. 14.) 



MiCROCTSTiNA PERPucATA, Bensoii. (Plate XCII. fig. 4.) 



Helix perfucata, Beus. A. M. N. H. 1853, sii. p. 93 ; Pfr. Mon. 

 Hel. vol. iv. p. 50 ; Hanley, Conch'. Ind. p. viii (not figured). 

 Eemiplecta (sec. G) jierfucata, Theob, Si;pp. Cat. p. 22. 

 Microcystis 2^('rfucata, Clessiu, Nomen. Helic. \). 37. 



Original description : — " Testa vix perforata ,clepressa ^ transhicen, 

 2m7-piireo-fusca,politissima, spira elevutiuscula, sutura suhmarginata, 

 apice ohtvso ; anfractihus 4, convexiusculis, arete convohdis, ultimo 

 rotuiidato, subtus convexo ; apertura lunata, vix ohliqua ; peristomate 

 recto, acuto, marrjine columeUari verticali, leviter rejlexo, umbilico uon 

 pervio. 



" Diam. niaj. 5, min. 4, axis 3 mill. 



" Hah. in pago Gallensi, inter saxa. 



" Remarkable for its deep clear purple-brown colour." 



MiCROCYSTINA PERFUCATA, Var. BINTENNENSIS. (Plate XCII. 



figs. 3-3 i.) 



Bintenne, Ceylon (Collett). 



The sculpture is fine and longitudinal, 14 = 0-50 inch. 



Animal. The mucous gland is linear, the extremity of foot square, 

 the end above the gland projecting over it. Pallial margin broad. 

 The sole of foot divided. There is a right shell-lobe, no left shell- 

 lobe ; the left dorsal lobe is in two separate flaps. 



The jaw has a large central projection. 



The teeth of the radula are arranged thus : — 



30 . 1 . 8 . 1 . 8 . 1 . 30 

 39 . 1 . 39 



This formula agrees very well with that of M, rinbii, Morch 

 (Vol. I. p. 11), of the Andaman Islands. 



The male organ was in good preservation. It presents a simple 

 straight sheath, tapci'ing above to the retractor muscle. The vas 

 deferens appears to join it just below this point, but it really does 

 so at the side much lower down. This is indistinctly shown in 

 fig. 3 rj, but on placing the object between two glass slips, and with 

 light pressure, it was very clearly seen. The rest of the genitalia 

 was not made out. The buccal mass has a very strong basal muscle ; 

 the salivary gland is a globose mass. 



Although the columellar margin in these Ceylon species is not 

 exactly of the same form as in typical Microcystina of the Andamans, 

 I have no hesitation in placing them together, there being so many 

 other more important characters common to both. The radula is 

 the same in number and form of the teeth, both have a right shell- 

 lobe and no amatorial organ, and the type of sculpture is the same. 



