406 MESSES. MELYILL AND STANDEN ON [June 18, 



CoLUMBELLA (Semhstelia) selasphoea \ sp. n. (Plate XXIII. 

 fig-7.)_ 



C. minuta, ovata, plerumque obesida, solidiuscula, cinereo-straminea, 

 flammis fulgetrinis rufo-fuseis pulchi'e dispositis; anfractibus 6-7 , 

 quorum apicales tres globulosi, vitrei, cceteris regulariter costis 

 longitudinalihns, Icevibus, rectis, decor atis, uUimi anfr actus ad 

 tredeeim, interdum supra hasim evanidis, interdum, sed rarius, 

 dorsaliter undique Icevibus ; ajpertura anguste oblonga, labro 

 paullum incrassato, Icevi, intus paucidenticulato ; columella nitida^ 

 simplici. 

 Long. 3, kit. 1^ mm. 

 Hab. Karachi. 



According to Mr, S. Pace, this species has hitherto been con- 

 foundfcd with C. troglodytes 8oav., from New Caledonia, or C ornata 

 Pease. It is by the former name that we have for years labelled 

 it in om' collections. Tliere are, dispersed over the tropics of both 

 hemispheres, about a dozen or more closely-allied species of Semi- 

 nellce, mostly gregarious, and collected in handfuls where they 

 occur, and which only acute systematic research can hope to 

 successfully differentiate. This species is principally conspicuous 

 for its smooth longitudinal ribs, with no revolving lines, the ribs 

 themselves being often obsolete on the last whorl, wholly or, at 

 all events, in part. The beautiful zigzag painting, hke lightning- 

 flashes, is also characteristic. 



CoLUMBELiA (Seminblla) townsendi, sp. n. (Plate XXIII. 

 fig. 8.) 



C. testa minuta, ovata vel obesula, brimnea vel castanea, vel 

 stramhiea, solida ; anfractibus 6-7, quorum apicales 1| albo- 

 lactei, cceteris ad suturas im,pressis, subturritis, longitudinaliter 

 crassicostatis, undique spiraliter liratis, liris ad juncturas 

 costarum gemmulatis, nitidis, interduni ad medium anfractus 

 idtimi absentibus aut partim evanidis ; apertura anguste oblonga, 

 labro incrassato, intus denticulato ; columella recta, simplici, haud 

 multum incrassta. 

 Long. 3-50, lat. 1'50 mm. 

 Hab. Karachi. 



A variable and locally abundant species, at first thought to be 

 identical with 0. ostreicola Sowb., or its ally C. nigricaiis Sowb. ; 

 both these being s|jecies of the New World. In the opinion of 

 Mr. Pace it is sufficiently distinct from both these, and from 

 G. atrata Gould, to need a cognomen and description. There appear 

 two varieties : one, the typical, uniformly thickly ribbed, chestnut 

 or brown unicolorous, crossed by revolving liraj entirely over the 

 surface ; while the other is spirally banded with darker brown, just 

 where the lirse are present, they becoming either partially or 

 entirely obsolete in the centre of the body-whorl, and in this 

 instance a central light fascia is exhibited. 



* aeXas, lightning ; ^epw, I bear. 



