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5. zacalles Melv. and S. zacalloides Schepm. but the callus at once distinguishes it from all the 

 species described as Solariclla. 



Solariellopsis n. g. 



Shell resembling Solariella, but differing in the radula, which is longer, with a larger 

 number of uncini. Teeth of the median part less denticulated. In "Die beschalten Gastropoden 

 der deutschen Tiefsee-Expedition, 1898 — 99" Prof v. Martens has (p. 124 — 127) described two 

 species "■patula" and "■ aethiopicd" under the generic name of Basilissa, and located two other 

 forms B. ottoi Phil, and var. Chimi in the same genus, on account of resemblance with B. patula, 

 with the type of the genus: B. lampra Watson, and Dr. Thiele (I.e. p. 161) has described 

 the radula. At my request Prof H. M. Gwatkin of Cambridge, had the kindness to send me 

 for comparison, the radula of a specimen of the typical species [B. lainpra)^ from the same lot 

 that served for the description in the "Challenger" report; which proved to be of so different 

 structure, as will be described in treating on that genus, that it is impossible, if one lays any 

 systematic value on the characters of the radula, to keep these species in the same genus. 

 It may be very difficult to find conchological characters to separate them, unless all the 

 species resembling 5". aethiopica^ prove to belong to the new genus. A separation will be only 

 possible, if the radulae of a much larger number of species have been examined, v. Martens 

 (I.e. p. 123) has observed that the characteristic sinus of the outer margin is conspicuous in 

 B. patula^ much less in B. aethiopica and wants in B. oitoi\ in the figure (I.e. pi. 4, fig. 17) 

 this is not visible, as v. Martens says, on account of the insufficient condition of that margin. 

 Pei'haps the sinus, which is conspicuous in Basilissa, will proove to give the best character 

 for that genus. 



To Solariellopsis belong the three species mentioned by v. Martens and 5. calcarata 

 now to be described below, moreover I have located in it, such species as seem to belong to 

 it by their shell characters, though I have just now demonstrated, how dangerous it is to classify 

 such species, without any knowledge of the soft parts. 



I. Solariellopsis calcarata n. sp. PI. IV, fig. 2; PI. IX, fig. 10. 



Stat. 302. 10° 27'. 9 S., 123° 28'./ E. 216 M. Sand and coralsand. i Spec. 



Shell depressedly conoidal, sharply keeled, with a flat base and large umbilicus; it is 

 nacreous under a thin, transparent, yellowish-white layer. Whorls sY^, slightly convex, especially 

 the last one. Nucleus smooth, shining. The sculpture consists on the upper whorls of rather 

 distant, radiating ribs, crossed about halfway by a spiral rib or keel, forming small, sharp 

 tubercles where they cross each other; on the third whorl, another series of tubercles appears, 

 at some distance from the deep suture ; on the penultimate whorl, the number of rows of 

 tubercles amounts to three and the suture is conspicuously crenulated by the keel, which rests 

 on the last whorl; this whorl is adorned by 5 spiral rows of tubercles, of which the second 

 from above is the smallest, moreover the keel is surmounted by short, conical, rather sharp 

 spines of which 38 are visible, if seen from below. Base nearly flat, more convex towards the 



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