74 SCALARIA. 



Section OPALIA, H. & A. Adams, 1853. 



S. DIAN.E, Hinds. PI. 15. fig. 74. 



Whitish, whorls 1 ventricose, smooth, very rapidly enlarging, lamellae 



distant, broadly expanded above. Length, 9 mill. 



Amboyna. 

 S. CONSORS, Crosse and Fisher. PI. 13, fig. 11. 



Narrow, whitish, whorls 11, rounded, in contact, with regular 

 simple lamellae, base with spiral rib. Length, 13 mill. 



St. Vincent's Gulf, Australia* 



S. PHILTATA, Watson. PI. 18, fig. 78. 



Thin, subhyaline, white; whorls 7, flatly convex with deep suture, 

 with about 25, longitudinal oblique lamellae, cut across by two or 

 three strong spiral furrows, causing the lamellae to appear in prickly 

 interrupted series, base with a spiral thread. Length, 2'5 mill. 



Tristan d'Acunha, (100 to 150 fms.) 



S. LAMELLOSA, Lam. PI. 15, figs. 84, 76, 77, 82, 83. 



Whorls about 8, well rounded, smooth, flesh color, more or less- 

 definitely darker banded at the suture and above the basal rib, and 

 intermediately marbled, lamellae thin, white, blade-like, continuous. 



Length, 1-1 '5 in. 



Mediterranean, West Indies, Sandwich Is. Mauritius* 



I include here several species which I find it impossible to* 

 separate by characters of value. Morch (Jour. Philad. Acad. VIII, 

 200) says that the Mediterranean S. pseudoscalaris, Brocchi (fig. 77) 

 differs in being narrower, with equal ribs, and that the Polynesian 

 S. perplexa, Pease (fig. 83), has single high, alternating with pairs 

 of lower ribs; but both these forms differ widely in series of 

 specimens and are clearly traceable one into another. 



I also include here S. coronata, Lam. (fig. 76) said by Kiener to 

 come from Cape of Good Hope, and by Morch believed to be West 

 Indian : it appears to be merely a well-grown S. lamellosa, the number 

 of lamellae varying. 



This is 8. clathrus of Linnaeus, 12 Edit, (not 10th Edit.) and of 

 most American authors, and S. monocycla, Lam. (fig. 82). Mon- 

 terosato has given the new name of commutata to the Mediterranean 

 specimens because, he says, that of S. lamellosa is preoccupied by 

 Brocchi for a large Grignon fossil, and the true S. pseudoscalaris, 

 Brocchi is somewhat spinose. It does not seem advisable again to 



