634 ON SHELLS FROM SUMATRA AND BORNEO. [May 17, 



7. ScARABUs BORNEENsis, A. Adams. 

 Only one specimen, found at Bandjermasin. 



8. Pterocyclos MiNDAiENSis, sp. n. (PlateLV. figs. 8, Sfl, 86.) 

 Shell depressed, orbicular, rather solid, dark reddish brown, 



varied with zigzag narrow white markings both above and below, 

 covered with a greenish-brown velvety epidermis bearing two 

 series of close-set short hairs, one above and the other beneath the 

 periphery, the former winding up the suture. These cilia are inva- 

 riably worn off in adult shells. Whorls 5, rounded, divided by a 

 deep suture, marked with distinct spiral striae and lines of growth. 

 Peristome double, outer margin considerably expanded, especially at 

 the upper part where it joins the body-whorl, but less reflexed than 

 towards the base. Inner margin simple. Greatest diameter 19 

 tnillim., axis 5. 



Operculum very concave exteriorly, consisting of seven narrow 

 whorls which are coarsely obliquely striated, with the outer margins 

 exserted at the sutural line. 



This species very closely resembles P. lowianus, Pfr., from the 

 island of Labuan. It is, however, rather larger, has a darker and 

 thicker epidermis, which is ciliated, that of P. lowianus, as far as we 

 know, lacking that peculiarity ; and the peristome is more expanded 

 and reflexed. The opercula of these two forms present such difference 

 of character as to indicate at once their specific distinctness. 

 That of P. lowianus has exteriorly a deep groove separating the 

 whorls, which stand up erect and lamelliform. In P. mindaiensis the 

 whorls rest one upon another, and the surface is regularly concave. 



Hab. Mindai (Amontai district) ; exceedingly common amongst 

 the decaying leaves. 



Borneo is especially rich in specimens of the genus Pterocyclos. 

 In some places, particularly at Mindai, the ground was literally 

 swarming with Pt. mindaiensis ; they keep amongst and feed on de- 

 cayed leaves. 



9. Opisthoportjs euryomphalus, Pfr. 



Only two specimens from Long Wai, Koeti ; one has the tube 

 directed the opposite way. Two specimens from Mindai. 



10. Leptopoma (Pfr.) lowi, Pfr. 



ILL. DUPLICATUM, Pfr. 



12. L. BARBATUM, Pfr. 



13. L. suBcoNicuM, Pfr. 



14. L. MASSENA, Less. 



All from Mindai. Only a couple of specimens of each found. 



15. Cerithidea (Sow.) obtusa. Lam. 



Abundant at Bandjermasin in the swamps ; they were more on 

 land than in the river. Amongst the numbers collected I only found 

 one with perfect apex. 



