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Diam. maj. sYa, alt. 4"/^; apert. alt. 2^/4, lat. 2Y2 Mill. 



Allied to the preceding species, but more depressed, with two denticles on the columella 

 and differing also by many particulars of sculpture. 



8. Solariellopsis concavospira n. sp. PI. V, fig. i. 



Stat. 178. 2°40'S., I28°37'.5E. 835 M. Blue mud. i Spec. 



Stat. 286. 8°50' S.,° I27°2'.2 E. 883 M. Mud, evidently a thin layer. 3 Spec. 



Shell depressed, with a conical spire, having a concave outline of the upper part, thin, 

 with a very thin yellowish outer layer, only appreciable in a dry state, the shell being entirely 

 nacreous if wet, with exception of the uppermost whorls, which are whitish ; whorls 6, rather 

 convex. Nucleus smooth, next whorl with radiating ribs; the subsequent whorls have 2 spiral 

 keels, they are, like the last whorl, excavated near the suture; this excavation is bordered by 

 the uppermost keel, which is adorned by short, rather sharp spines, 27 in number on the last 

 whorl. Between this keel and the peripheral one, runs a second spiral keel with 39 smaller 

 spines; on the peripheral keel, they are still more numerous, and have more the character of 

 compressed folds, which extend a little upwards and less downwards, the upper part being also 

 visible on the upper whorls, like small folds, bordering the linear suture ; the space between 

 the 1=' and 2^ keel is traversed by folds, running downwards from the spines of the upper keel, 

 they often, but not always, reach the 2^ keel, which projects also small folds in both directions, 

 which however are shorter and don't reach the next keels; the space below the suture is likewise 

 provided with folds, partly projecting from the upper keel, partly free. Base of the shell a little 

 convex, with three spirals, which are slightly crenulated, and a strongly crenulated spiral (in 

 one specimen accompanied by a secondary one) bordering the large umbilicus, which is pervious, 

 funnel-shaped, its wall with elegantly curved, riblike striae or folds, which extend over the base 

 of the shell, the infraperipheral space only remaining smooth. The whole shell is covered with 

 very fine growth -striae, visible only under a lens. Aperture rounded-quadrangular, margins sharp, 

 upper margin convex, basal one more straight, but still convex, columellar margin curved and 

 forming a distinct angle with the basal margin, at the end of the umbilical keel. Columellar 

 and outer margins connected by a very thin, nacreous layer. Interior of aperture nacreous. 



Alt. 6,- diam. maj. 8^/.j; apert. alt. 3Y3, lat. 3Y„, diam. of umbilicus 4 Mill. 



The nearest allies of this species seem to be Solariella actinophora Dall and S. effos- 

 sima Loc, but it differs in many particulars of sculpture, a. o. the new species has not the 

 spirals in the umbilicus, on which Locard lays much value, and effossima is a thicker species; 

 S. actinophora is less depressed, though apparently similar in the shape of the spire. 



I at first located this species in Solariella^ before I knew the dentition of the species 

 now located in Solariellopsis^ but now I think it may be removed with equal right to the new 

 genus Solariellopsis. 



9. Solariellopsis metallica Wood-Mason & Alcock. 



Wood-Mason and Alcock. Ann. Mag. Nat. Hist. Ser. 6, Vol. 8, 1891, p. 444, with figures 

 in the text. 



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