1890.] MARINE MOLLUSCA OF ST. HELENA. 295 



lata; apertura rotundata ; peristoma leviier incrassatuin, 

 marginihus continuis, dextro subpatulo. 



Longit. | millim., diam. maj. Ig. 



The beauty of this species can only be seen under the microscope. 

 The cancellation of the bocly-vvhorl is strongly developed, so that 

 the pittings between the cross-ridges are deep and striking. The 

 uppermost of the six revolving liriB borders the channelled suture, 

 and the umbilicus is encompassed by a swollen ridge, which is in 

 addition to the six lirte referred to. The microscopic strife are seen 

 upon the lirse. 



LiOTiA ADMiKABiLis. (Plate XXIV. fig. 7.) 



Testa minuta, profunde iimhiJicnfn, depresae globom, (ilba ; an- 

 fractus 3i, auperne declives, planulfiti, in medio angulati, 

 infra angulinn plaiii, cancelluti. iiltimua carinis transversis 

 qiiinqiie, la/iiellis longitttdinalibits paitlo ohliquis circiter 1() 

 instriiclus ; apertura circiilarin ; peristoma incra.ssatuni, con- 

 tinuum, marginihio; callo tenui junctis. 

 Longit. i miUiin., diam. maj. I3. 



This very minute species is a strongly sculptured shell like 

 L. asterisc.us, Gould, and L. speciosa, Aiigas. It is, however, much 

 smaller than either. 



Tlie uppermost of the keels on the body-whorl revolves up the 

 spire and forms the angle on the upper volutions ; the lowermost 

 carina borders the umbilicus, and the next occupies the middle of 

 the under surface. The longitudinal lamellae are continuous on and 

 between the keels. 



Gen A ASPERULATA, A. Adams. 



Genu asperulata, A. Adams, Proc. Zool. Soc. 1850, p. 38; Thes. 

 Conch, vol. ii. p. S31, pi. 173. figs. 28, 29 ; Sowerby, Conch. Icon. 

 pi. ii. fig. 16. 



ITab. — ? (Adams) : St. Thomas (Brit. Mus.). 



The colour of this species is very variable. Some specimens are 

 pink, tessellated «ith white; others are olive-brown with white 

 spots ; some have few spots, others many. None of the St. Helena 

 shells are marked like the type, but they agree with it in form and 

 sculpture, which is peculiar, and in having the apex of the spire 

 white. 



Emarginula elongata, Costa. 



Hah. Mediterranean. 



A single small specimen, 5 millim. in length, apparently belongs 

 to this species. The cancellation of its surface is, however, a little 

 finer than usual. E. maculata, A. Adams, from Japan, also closely 

 resembles this specimen in form and sculpture. 



FissuRELLA gibberula, Lamarck ? 



Several specimens, the largest of which is hardly ten millim. 

 long, appear to belong to this species. F. variegata. Sow., and 



