MONILEA-MINOLIA. 259 



Subgenus MINOLIA A. Adams, 1860. 



Minolia A. AD. Ann. & Mag. Nat. Hist, iv, 1860, p. 336. 

 FISCHER Manuel de Conchyl., p. 824. Solariella H. & A. ADAMS, 

 Genera Rec. Moll., i, p. 431. WATSON, Challenger Gasteropoda, p. 

 72 (not Solariella Searles Wood). Minosia Ad. DUNKER, Ind. Moll. 

 Mar. Jap., p. 142. 



Minolta includes a number of broadly umbilicated thin-shelled de- 

 pressed trochids, with cylindrical or angulated whorls, and fine 

 decussated sculpture. They are like Monilea in many respects, differ- 

 ing in the simple umbilicus, which has no spiral callous funicle 

 within it. The species belong to the Indian Ocean, western and 

 southwestern Pacific. As is the case in many groups of Trochidse, 

 I have been obliged to select the species belonging here out of a 

 number of very dissimilar genera or subgenera ; and I doubt not that 

 still more forms, referred heretofore to Gibbula, Margarita, or simply 

 Trochus, will be found to group in Minolta. The dentition and 

 animal are unknown. The use by some authors of the name Solariella 

 for this group is obviously indefensible. At the same time, it must 

 be admitted that no character in the shells really separates Minolia 

 and Solariella. It remains to be seen whether the dentition will con- 

 firm their separation. In the arrangement of the genera of Trochidse 

 it must be admitted that we are all at sea. The systems proposed 

 by various authors break down at so many points that their artificial 

 nature becomes obvious. Nevertheless, there undoubtedly is a 

 natural classification to be ascertained ; this awaits a fuller knowl- 

 edge of the anatomy of the group. The type of the group is 

 M. punctata Ad. 



M. PUNCTATA A. Adams. PL 44, fig. 33. 



Shell helicoid, widely umbilicated, fulvous, punctate with red ; 

 whorls 6-2, convex, traversed by spiral granulose cinguli ornamented 

 with red dots, and alternately larger and smaller, the interstices 

 beautifully clathrate with delicate oblique lamellae ; suture canalic- 

 ulate ; umbilicus perspective, with concentric granulose cinguli, the 

 interstices closely clathrate. (A. Ad.} 



Id. of Mino-Sima, near Niphon, Japan. 



Minolia punctata AD. Ann. Mag. N. H. 1860, p. 337. Magarita 

 punctata Ad., SOWB. Conch. Icon., f. 14. 



This is another .modification of the hollow spiral cone of the Tro- 

 choid family ; the whorls are somewhat loosely rolled on themselves. 



