MOLLUSC A. 51 



A single dead specimen only was obtained, destitute of colour and choked 

 with sand. It is remarkable from its rounded base and its very expanded umbi- 

 licus, which is proportionately larger than in any other species. In S. perspec- 

 tivum the umbilicus is equal to a third of the diameter, but in the present species 

 it is two-fifths. 



208. Solarium calatum, Hinds, 1. c. p. 25, (Plate XIV. fig. 11, 12.) Testa parva, valde 

 discoidea, nitida, fusca ; spira. nulla; anfractibus prope suturam uniseriatim tuberculatis, medio 

 eleganter radiatim plico-striatis ; ad peripheriam carinis duabus obtusis tuberculatis ; ad basin 

 rotundata; apertura subrotunda; umbilico valde patulo, crenis parvis numerosis armato. 



Inhab. Straits of Macassar ; in ten fathoms, among coarse sand. 



209. Solarium dealbatum, Hinds, 1. c. p. 24, (Plate XIV. fig. 13, 14.) Testa conico-trochi- 

 formi, alba; anfractibus planulatis, quadiiseriatim granulato-costatis ; cingulo ultimo paulo majore, 

 prominulo ; umbilico coarctato, crenis parvis instructo ; arta. umbilicali multicostata; apertura 

 rotundata.. 



Inhab. Manila. 



This species may be readily distinguished from S. variegatum by its uniform 

 colour and by the several ribs which cross the umbilical space, all of which are of 

 equal size ; from S. cylindraceum by its decided conical shape, and the characters 

 detailed above observable in the inferior girdle. 



It is unquestionable that a sound division of the genus may be effected, by 

 taking S. variegatum as the type of a new group ; and this opinion rests on the 

 conformation of the foot of the animal, decidedly sessile eyes, and very peculiar 

 operculum of this species. But in trying to effect this I have met with the follow- 

 ing genera, all of which have been advanced for sections of the genus as left by 

 Lamarck: — Omalaxis, Deshayes ; Bifrontia, Deshayes ; Heliciles, Schlotheim ; 

 Cirrus, Sowerby ; Eiiomphaliis, Sowerby ; Schizostoma, Bronn ; Solariella, Searles 

 Wood ; Torinia, Gray ; and not having before me the materials for deciding their 

 respective merits, and being averse to treating the difficulty as a gordian knot by 

 the erection of another genus, I am compelled to leave the subject as I found it. 



210. Solarium fragile, Hinds, I.e. p. 24, (Plate XIV. fig. 15, 16.) Testa orbiculato-dis- 

 coidea; anfractibus quadiiseriatim tuberculato-cingulatis ; cingulo supremo et ultimo fusco pictis, 

 medianis margaritaceis ; ad peripheriam angulata, crenulata. ; basi tumido; umbilico patulo, crenis 

 parvis albis acutis cincto ; area umbilicali laevi ; apertura triangulari. 



Inhab. North coast of New Guinea. In seven fathoms, sand. 



211. Solarium fulvum, Hinds, 1. c. p. 24, (Plate XIV. fig. 17, 18.) Testa orbiculato-dis- 

 coidea., solidula, fulva ; spira retusa; anfractibus multiseriatim granuloso-cingulatis, medianis mino- 

 ribus ; ad peripheriam obtusa., carinis duabus, tertia minore intermedia; basi rotundata, seriatim 



