274 MINOLIA-CIRCULUS. 



but that is flatter and has a much wider umbilicus. The name is 

 derived from the white spots which fleck the shell. 



T. (Solariella*) albugo WATSON, Journ. Linn. Soc. Lond. xv, p. 

 94 ; Challenger Gasteropoda, p. 75, t. 6, f. 8. 



Unfiyured Species of Minolta. 



SOLARIELLA UNDATA Sowerby. Testa subdepressa, umbilico ro- 

 tuudo usque ad apicem perforata, margaritacea, pallide rubescente, 

 spiraliter tenuiter lirata, supra prope suturam angulata ; medio 

 anfractuum carina rotundato-angulata, angulis distanter rubro 

 maculatis ; interstitiis rubro undato-lineatis. (SowB., P. Z. S. 1870, 

 p. 251). 



Agulhas Bank, S. Africa. (Mus. Taylor.*) 



Genus CTRCULUS Jeffreys, 1865. 



Circulus JEFFREYS, Brit. Conch., iii, p. 315; Proc. Zool. Soc. 

 1883, p. 94. FISCHER (as subgenus of Qibbula), Man. de Conchyl., 

 p. 824. 



Jeffreys's diagnosis of this group is as follows : Shell coin-shaped 

 or forming a circular compressed disk, slightly nacreous or pearly ; 

 mouth quadrangular, with a discontinuous peristome ; umbilicus very 

 wide ; operculum multispiral as in other genera of Trochidse. The 

 animal is unknown. 



C. STRIATUS Philippi. PL 66, figs. 11, 12, 13. 



Shell minute, discoidal, depressed above, broadly umbilicated 

 beneath, subtransparent, quite solid, white ; surface shining ; spire 

 depressed, composed of 4 to 5 convex whorls, traversed spirally by 

 sharp narrow lirse, 7-9 in number on the upper part of the last whorl, 

 half as many on the penultimate whorl, two or three on the next, the 

 two upper whorls smooth ; the inter-liral spaces delicately obliquely 

 marked by growth striae. The lowest ridge is placed just under the 

 periphery, and is sometimes more prominent than the rest ; suture 

 impressed ; whorls cylindrical, gradually enlarging, the last broadly 

 concave beneath, and smooth save for slight radiating lines of 

 growth ; aperture oblique, rounded-quadrangular ; peristome not 

 continuous ; columella arcuate, subreflexed at the umbilicus ; outer 

 lip slightly sinuous above ; umbilicus broad, deep, showing all the 

 whorls. Alt. '8, diam. 2'5 mill. 



Mediterranean and Adriatic Seas; Atlantic Ocean, England to 

 Morocco. 



