Geological Society. , 137 



traordinary collection ; it is probably the same as Kiener's F. lyri- 

 forniis, but it is not the same as Broderip's, which is identical with 

 Swainson's Mitra lyriformis. Its papillary apex closely resembles 

 that of V.fulminata. 



VoLUTA GuiLDiNGii. Vol. tostd obloTigd, crassd, fulvesceute, line" 

 oils saiuratioribus aliisque albis pictd ; spird acuminatd, apice ob- 

 tuso : anfractibus 5 ad 6, subventricosis, longitudinaliter costatis, 

 interstitiis costarum transversim striatis, ultimo magna, Iceviga' 

 tiusculo ; aperturd mediocri, labio externa extus incrassato, albi- 

 cante, intus dente parva insiructa ; columelld plicis quinque ad sex 

 parvis, anticis duabus validioribus. 

 Shell oblong, thick, fulvous, marked with little white lines and 

 others of a darker colour ; spire acuminated, with an obtuse apex ; 

 volutions five to six, rather ventricose, longitudinally ribbed, inter- 

 stices of the ribs with transverse striae, the last volution large, rather 

 smooth ; aperture middle-sized, outer lip externally thickened, whitish, 

 furnished with a small tooth internally ; columella with five or six 

 small folds, of which the two anterior are more prominent. 



This is the smallest known species of Volute ; it was discovered 

 at St. Vincent's by the late Rev. Lansdown Guilding. In Mr. Cu- 

 ming's and Mr. Metcalfe's collections. 



VoLUTA Cylleniformis. Vol. testd parvd, ovatd, crassd, Itevius- 

 culd, albicante, maculis parvis jlavicantibus sparsim ornatd; spird 

 subconicd, anfractibus sex, postice coarctatis, ad suturam gra^ 

 nosis, antice longitudinaliter costatis, ultimo magna, antice trans- 

 versim striata ; canali parvo, rejlexo ; aperturd oblongd, labia ex- 

 terno extus incrassato, margine interna intus dente parvo instructo; 

 labia columellari antice ruguloso, dentibus tribus parvulis munito. 

 Shell small, ovate, thick, rather smooth, whitish, sprinkled with 

 small yellowish specks ; spire somewhat conical, with six volutions, 

 which are contracted posteriorly, granose at the sutures and longi- 

 tudinally ribbed anteriorly ; the last volution is large and anteriorly 

 trnnsversely striated ; canal small, slightly reflected ; aperture oblong, 

 outer lip externally thickened, its internal edge furnished with a 

 small tooth ; columellar lip rugulose anteriorly, furnished with three 

 small teeth. 



The only specimen I have seen of this curious little shell is in 

 the collection of W. Metcalfe, Esq. In general appearance it nearly 

 resembles a Cyllene. 



GEOLOGICAL SOCIETY. 



Dec. 4, 1844. — A paper was read, entitled, "Remarks on the 

 Geology of British Guiana." By the Chevalier Robert H. Schom- 

 burgk. 



The geology of the district of British Guiana is chiefly confined to 

 primitive rocks. At the mouth of the Orinoco is an extensive delta 

 consisting of blue clay, which, when pierced, gives a supply of water, 

 and Artesian wells have been sunk here in many places with success. 

 Below the clay appear the remains of an ancient forest. The allu- 



Ann. ^ Mag. N. Hist. Vol. xv. L 



