Zoological Society. 439 



very expanded umbilicus, which is proportionately larger than in any 

 other species. In S. perspectivum the umbilicus is equal to a third 

 of the diameter, but in the present species it is two-fifths. 



6. Solarium dorsuosum. Sol. testd conoided, lavic/atd, solidd, 

 fused, albo confuse nebulosd ; anfractlbus plajiu/atis, spirnliter seri- 

 atim sulcatis, spircB leviter striatis ; ad pcripheriam sulcis geminis 

 instructd; basi sulcatd, versils centrum subtxibercxdatd ; umbilico 

 patulo, crenis magnis cincto ; ared umbilicali unicostatd ; aperturd 

 subrotundatd, interne bisulcatd. Alt. 4, diam. 6^ lin. 



Hab. Puerto Galero, island of Mindoro, Philippines ; in seven fa- 

 thoms, sandy mud. 

 Cab. Cuming. 



7. Solarium dealbatum. Sol. testd conico-trochiformi, alba; 

 anfractibus planiilatis, quadriseriatim granulato-costatis ; cingulo 

 ultimo paulb majoi-e, prominulo ; umbilico coarctato, crenis parvis 

 instructo ; ared umbilicali multicostatd ; aperturd rotundatd. 

 Alt. 7, diam. 6 lin. 



Hab. Manila. Cab. Hinds. 



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, l)y taking S. variegatum as the type of a new group ; and 

 this opinion rests on the conformation of the foot of the animal, de- 

 cidedly sessile eyes, and very peculiar operculum of this species. 

 But in trying to effect this I have met with the following genera, all 

 of wliich have been advanced for sections of the genus as left by 

 Lamarck : — Omalaxis, Deshayes ; Bifrontia, Deshayes ; Helicites, 

 Schlotheim ; Ciri'us, Sowerby ; Euomphalus, 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. 



8. Solarium fragile. Sol. testd orbic.ulato-discoided ; anfractibus 

 quadriseriatim tuberculato-cingulatis ; cingulo supremo et ultimo 



fusco pictis, medianis margaritaceis ; ad peripheriam angulatd, 

 crenulatd ; basi tumido ; umbilico patulo, crenis parvis albis acutis 

 cincto ; ared umbilicali Icevi ; aperturd triangulari. Alt. 1, diam. 

 3 lin. 



Hab. North coast of New Guinea ; in seven fathoms, sand. 



Cab. Belcher. 



9. Solarium fulvum. Sol. testd orbiculato-discoided, soliduld, 

 fulvd ; spird retusd, anfractibus multiseriatim granulosO'Cingulatis, 

 medianis minoribus ; ad peripheriam obtusd, carinis duabus, tertid 

 minore intermedid ; basi rotundatd, seriatim granulatd ; umbilico 

 mediocri, crenis concoloribus cincto ; ared umbilicali leviter uni- 

 costatd; aperturd subquadratd. Alt. 1^, diam. 3^ lin. 



Hab. New Guinea. Cab. Belcher and Hinds. 



