246 On new Species of Land- Mollusca from Borneo. 



This very beautiful shell is another spined form, a com- 

 petitor for the admiration of the conchologist with Opisilio- 

 stoma grandesjnnosa, lately described by me ; in this species 

 the spines are not so large and have more the character of 

 raised rings. 



Opistlwstoma Hosei, sp. n. (PI. VII. fig. 2.) 



Shell pyramidal, very narrowly perforate ; sculpture of the 

 upper whorls quite smooth, tlie free portion of the last being 

 strongly costulate, the ribs near the aperture being in high 

 relief ; colour shining ochre ; spire conic, flat-sided, apex 

 blunt ; suture shallow ; whorls 5, flat, the last free, with con- 

 siderable twist, compressed, producing a keel ; aperture 

 circular ; peristome widely expanded. 



Size : major diam. 1"8 ; alt. axis 1'6 millim. 



Locality. Baram district, Borneo [C. Hose). 



This is another very distinct form from the same part of 

 Borneo. In the very smooth surface of the first five whorls 

 it is unlike any species with which I am acquainted. 



Diphmmatina Aldrichi^ sp. n. (PI. VII. fig. 3.) 



Shell elongately turreted, rather solid ; sculpture strong dis- 

 tant costulation ; colour dull ochre j spire becoming rapidly 

 pointed, apex sharp ; suture well impressed j whorls 8, convex, 

 the constriction in centre above the aperture, penultimate the 

 largest and rapidly decreasing in size above ; aperture ovate- 

 vertical ; peristome double, expanded ; columeilar margin 

 vertical and angulate below. 



Size: maj. diam. 1*75 ; alt. axis 3*75 millim. 



Locality. From either the Kusan or Penggiron districts, 

 S.E. Borneo {William Doherty). 



This shell is identified as D. concinna^ H. Adams, in " List 

 of Shells from Borneo," published in the 'Journal of the 

 Cincinnati Society of Natural History,^ April 1889, p. 25, by 

 Mr. T. H. Aldrich. This gentleman has very kindly sent 

 his specimen to me to examine, and this I find does not agree 

 with Adamses species. 



EXPLANATION OF PLATE VII. 



Fig. 1. Ojnsthostoma jmlchella, sp. n., X 12. 



Fir/. 2. Ojjitt/wstoma Hosei, sp. n., X 12. 



Fiff. 3. Uiplommatijia Ahlrichi, sp. n., X 7. 



Fig. 4. Bhiostoma iris, Godw.-Aust., X 2-5. 



Fig. 5. Hhiosfomct Hungerfordi, Godw.-Aust., X 2'5. 



I 



