Mr. W. H. Benson on the genus Tomichia. 379 



Dr. PfeiflFei*'s description of the species is as follows : — 



" T. ventricosa. Sow. Testa rimata, adulta truncata, cyliudraceo- 

 turrita, solida, IseTigata, cfrnea ; aiifr. 4|- convexiusculi, sensim 

 accresceutes, ultimus ventricosus, antice plurivaricosus ; apertura 

 verticalis, elliptico-ovalis ; perist. siibdiiplicatum, iiiargine externo 

 refato, interne \'ix proraineute, continiio, ad columellam reflexius- 

 culo. Operc. tenue, fusco-nigricans. 



" Long. 7, diam. anfr. penult. S mill. Apertura 2\ mill, longa, medio 

 If lata. 



" Jan. T. turrita, apice acuminata {p\ anfr.) 5 mill. long. 



" Truncatelia ventricosa. Sow. MSS. ; Reeve, Conch. Syst. ii. t. 182. 



f. 2. 

 " Truncatelia capensis, K auss in litt. 

 "Habitat in Promoatorio Bouse Spei, Zwellendam (Krauss)." 



To the above n^ay be added, Anfractus peuultimns ssepe mal- 

 leatus, ultimus fere ruhens ; apertui'a iutus nitida, fuscata. I 

 have full-gruwn specimens possessing six whorls. On referring 

 to Dr. Kraass's ' Sudafrikanischen MoUusken/ it appears that he 

 gathered his specimens in marshes on the Cape Flats, as well as 

 in Zoetendal Valley, but it does rot appear that he examined and 

 took any note of the animal. I also caj'tured specimens, chiefly 

 in the Cape Flats, in a marsh near Baszaarnis Kraal, to the right 

 of the main road from Wynbergto Muysenberg, and beyond the 

 12th milestune from Cape I'own. There the water is ordinarily 

 fresh ; although I understood that in severe southerly gales, 

 when the " vlei," or mere, near Muysenberg is invaded by the 

 sea from the head of False Bay, the water has been known to 

 flow over the road ; thus, for a time, rendering the marsh in 

 question brackish. However this may be, I captured a single 

 live specimen at Michelville (or Holloway^s Halfway House), 

 in a freshwater ditch communicating with the little wayward 

 stream called Kuel, which discharges itself, probably through the 

 Erste Rivier, into False Bay, after a course of at least sixteen 

 miles. In this ditch it was accompanied by living examples of 

 a new species of PJujsa. At Baszaami's Kraal the adult speci- 

 mens, for the most part, crept about on the moist earth by the 

 edge of the water ; but the younger individuals were immersed, 

 in company with a small soleniform Cypris. I observed that, 

 aided by the lightness of their shells, the young Tomichice were 

 enabled to swim resupinate at the sui-face ; a habit common to 

 the fluviatile Pulmonifera both operculated and inoperculate, and 

 which is equally shared by the Succinea* of which I narrated 

 the voluntary resort to this act, in page 255 of the 6th volume of 



* Dr. Pfeiffer, to whom I forwai'ded a specimen of this Succinea, con- 

 siders it a new and distinct species, to which he has assigned the name of 

 S, Delalandii, Pfr. 



