SOLARIUM. 



Plate I. 



Genus SOLARIUM. Lamarck. 



Teda mbdepreiie conoidea,fulvesicente-spadicea,fu!)co varie 

 maculata et zo^mfa, »pird subohtitid, atifractibui aex 

 ad octo, angu»li», porrecie convolutii, umbilico per- 

 amplo, perspectito, columelld nulla, aperturd mibqiiad- 

 rangulari, purr:d. 



Shell somewhat depressly conoid, fulvous drab, variously 

 spotted and zoned with brown, spire rather obtuse, 

 whorls six to eight, narrow, convoluted in a wide- 

 spread manner, umbilicus verj- large, perspective, no 

 columella ; aperture nearly square, small. 



Genus Solarium is here restricted to the well-known 

 Linnsean Trochus perspectwrn and its allies, including 

 four small species, set apart by Dr. Gray as genus Phi- 

 lippia, of which the Mediterranean S. luteum is the type. 

 Dr. Gray's genus Torinia, embracing an interesting series 

 of small species hitherto referred to Solarium, will appear 

 as a separate monograph. They will be found to differ in 

 several important particulars from Solarium proper, and 

 thus to form a natural group of themselves. 



Twenty-one species, four of which it will be seen in the 

 course of our remarks are doubtful, are refeiTed in this 

 monograph to Solarium. They are characterized by a 

 more than common uniformity of growth, and even of 

 colour and marking. Composed of from six to eight 

 narrow obliquely quadrangular whorls, convoluted in an 

 unusually wide-spread manner, a very large umbilicus is 

 formed, penetrating to the inner wall of the apex, and 

 the innermost edge of the whorls being conspicuously cre- 

 nulated throughout, a curiously deceptive spiral line of 

 perspective is presented. The effect is best seen on look- 

 ing into the umbilicus — the hoUow axis of convolution — 

 with the shell held close to a lamp or to the flame of a 

 candle. The predominant colour of the shell of Solarium is 

 a yellowish or creamy-drab, and the marking consists of 

 bands, spots, and dots, of reddish-chestnut or brown. 



The animal of Solarium, which is furnished with a 

 horny operculum, partakes of the character of Trochus 

 and Turbo, and has the collar of the mantle reflected as 

 in those genera, but the head, instead of being shaped 

 like a proboscis, is prolonged into two elongated ten- 

 tacles, somewhat after the manner of Buceiuum and Pur- 

 pura. The region of the Islands of the Eastern Archi- 

 pelago is the principal seat of habitation of the species, 

 two, if not three of which range to Australia. It is doubt- 



ful whether there is any Solarium peculiar to Australia. 

 A small species, a very distinct one, S. oxylropis, recorded 

 from Xew Caledonia, does not appear to have been col- 

 lected elsewhere. S. einguluni and modedum are common 

 to the Philippine Islands, and to the Society and Sand- 

 wich Islands ; and a small abnormal species, S. InlKum. 

 inhabiting the Mediterranean, the only estratropical spe- 

 cies, unless one or two extend southwards beyond thai 

 limit, is found, like Zi-yphinns conuloides, in Australia 

 also. The Solaria of the New World are limited to a 

 characteristic type, represented in tropical America by 6'. 

 granulatum, verrucoaum, and quadriceps of Panama, Mexico, 

 and the West Indies, and .S'. placentale of the Bay of ilag- 

 dalena, California. 



Species 1. (Mus. Cuming.) 



SoLARICM PEEDIS. Sol. testd deprcsne conoided, tenui, 

 latigatd, pallidd, anfraclibui sublumidis, atiperne 

 cingulo unico dieim, ad spiram minute plicalo-ilriti- 

 tis, ad perip/ieriam angulatd, tricarinatd, carina me- 

 dia prominente, majore crenulatd, cingulo et carinis 

 maculi-i ri'Jis subquadralii ontalia, umbilico modice 

 patulo, crenuH.% parch albi» marginato. 



The paeteidge Solaeium. Shell depressly conoid, 

 thin, smooth, pale, whorls rather swollen, divided at 

 the upper part by a single belt, minutely plicately 

 striated at the spire, angled and three-keeled at ihe 

 periphery, middle keel prominent, the larger crenu- 

 lated, belt and keels oniamented with somewhat 

 square red spots, umbilicus moderately open, mar- 

 gined with small white crenules. 



HiXDS, Pro. Zool. Soc. 1844, p. 22. Moll. Voy. Sulpli. 

 p. 50.pl. 14. f. 3, 4. 



Eab. aiahicca, Ceylon, North- West Australia. 



A light and rather pale species, in which the red-brown 

 spots are comparatively feeble and rather distant. The 

 crenules of the peripher}' keel and of the margin of the 

 umbiHcus are conspicuous for their delicate pearl-like 

 character. 



Species 2. (Mus. Cuming.) 

 Solaeium pictum. Sol. te»ld subdepressi conoided, pur- 



April, 1S64. 



