OCR Text |
Show 1895.] BOBNEO A N D N E I G H B O U E I N G ISLANDS. 117 Although the differences between the extreme forms of this species are considerable, still there is such a general resemblance throughout the series, that it seems advisable to consider the various forms as local races of one and the same species rather than to describe them as distinct. The variation in the tongue-like reflection of the peristome over the umbilicus is one of degree, passing from the typical form, where it is obvious, to the var. pygmeea, where it is almost imperceptible. 50. ALYC^US HOSEI, Godwin-Austen. Alyceeus hosei, G.-A. Proc. Zool. Soc. 1889, p. 347, pi. xxxvii. f. 2. Hab. Busau and Rumbang Hills, Sarawak (Everett). In the description of this species the apex of the spire is said to be " pointed." In both the figure, however, and the shells also, it certainly is blunt. It is distinguished from A. elohrni thus: u apex distincte obtusior ; tubulus suturalis apertura? magis approxi-matus ; apertura subverticalis, non diagonalis ; peristoma utrinque distincte auriculatum, margine columellari cum basali angulum efficiente perdistinctum etc." (Dr. O. Boettger in litt.). 51. ALYCEUS (OETHALYCEUS) CONGENEE. (Plate III. fig. 26.) Testa A. hosei similis, sed minor, spira elatiore, graciliore, anfractu ultimo minus gibboso, peristomate expanso, duplice, margine columellari reflexo, ad umbilicum sinuato, haud oblique recti-lineare. Diam. maj. 5|- millim., alt. 6. Hab. Mulu and Barit Mountains, Sarawak. In colour and general appearance this species looks very like A. hosei. It differs, however, in the above particulars. It also, in some specimens, exhibits traces of spiral stria?. In Jwsei the inner peristome is somewhat porrected, in this form it is more reflexed. Thesinuation at the umbilicus is very peculiar. 52. ALYC.EUS (OBTHALYCJEUS) SADONGENSIS. (Plate III. fig. 27.) Testa A. fultoni similis, sed paulo minor, grisea, umbilico latiore, anfractibus quinque, oblique costulato-striatis et spiraliter striatis, ultimo minus gibboso, peristomate expanso, tenui, haud duplice. Diam. maj. 5jr millim., alt. 5-|. Hab. Sadong, Sarawak (Everett). Although not mentioned by Dr. Moellendorff in the following description, excessively minute spiral stria? exist in A. fultoni; tbey are visible only under the microscope, and are less observable than in the present species. The spire of the latter is slightly less elevated and the whorls more rounded than in A. fultoni. 53. ALYCEUS (OETHALYO/EUS) FULTONI, Mlldff. (Plate III. fig. 28.) " T. perforata, elate turbinata, sat tenuis, subpellucida, confertim costulato-striata, leete citrina ; spira valde elevata, subregulariter |