MOLLUSCA OP INDIA. 427 



Altc^tjs ptramidalis, Bs. (Plate CLVI. figs. G, 6 a.) 

 Bif. Coll. No. 45.06.4.4 B.M. 



Benson, A. M. N. H. xvii. 1856, p. 225; Hanley & Theobald, 

 Conch. Ind. pi. xci. figs. 5, 6 ; Theobald, Cat. Supp. p. 40 ; Nevill, 

 Hand-1. i. p. 293. 



Original description : — " Testa perforata, jVP''^'"^'^^^'^^'^'^^'*^^'^'^''' 

 Iceviuscula, confcrtim oblique arcuato-striatula, alhido-carnea, apicem 

 versus rubella; spira pyramidata, sutura valde impressa, apice 

 obtusiusculo ; anfraciibus 5 J valde convexis ; idtimo jpostice injiato, 

 turn constricto, dcinde subtumido, ajyerturam versus latiori, tubulo 

 calloso, elongato, retroverso, suturali, pone constrictionem oriente, 

 munito ; apertura ohliqua, subcircidari; peristomaie duplici, interno 

 continuo, ea-pansiusculo, externa expanso, rejlexiusculo, anfractu 

 p^emdtimo brevisshne angidatim adnata, sup>erne antice sinuata, turn 

 arcnato, ad umbilicuni leviter emargiaato. Operculo ? 



" Long. 12, axis 10, lat. 10 mill. 



" Hab. raro ad collem Therabuin, vallis Tenasserim. 



'"Nearly related to the Cochin -Chinese Ahjccvus gibbus, Fer., but 

 easily to be distinguished by its more pyramidal growth and by 

 the greater length of the spire in proportion to the breadth of the 

 last whorl, its more symmetrical proportions, sculpture, etc. The 

 origin of the sutural tube is about 4 millimetres from the anterior 

 margin of the aperture. This shell was met with at no other place 

 in the district, and seemed restricted to a spot of a few acres in 

 circumference. The hill is of limestone, steeply scarped and 

 almost inaccessible. Three species of Helix occurred there which 

 were similarly deficient elsewhere." 



I figure and describe below the Cochin China A. gibbus, Fer., 

 mentioned above, in order to show how it diff'ers from A.pyramidalis, 

 also because it was made by Wm. Blanford the type of his Section 1. 

 of the genus in his excellent paper " On the Classification of the 

 Cyclostomacea of Eastern Asia," Ann. M. N. H., June 1864, p. 441. 



Alyc^us (Orthalycjetjs) gibbus, Fer. (Plate CLVI. figs. 5, 5 a.) 



Locality. Cochin China, ex coll. Museum Cuming. Natural 

 History Museum. 



Shell globosely pyramidal, perforate, rather solid ; sculpture 

 fine, close, and regular striation throughout, becoming coarser and 

 costulate on the part next the moderately long sutural tube ; colour 

 dull white on last whorl, ruddy brown on apex; spire high, attenuate, 

 the apex smooth ; suture fairly impressed ; whorls, the last much 

 swollen, the three apical rapidly decreasing ; the constriction just in 

 Iront of the base of the sutural tube, then swelling forward towards 

 the aperture, this part very finely striate by lines of growth ; 

 aperture circular, oblique ; peristome double, the iuner lip thin and 

 sharply reflected ; columellar margin slightly curved and oblique 

 downwai'ds. 



Size : major diam. 11*0 ; alt. axis 7 mm. 



