368 RissoiA, 



throughout; whorls 7, convex, with deep suture; lip simple, con- 

 tinuous. 



Suez. 

 Section Actonia, Mouts. 1884. 



R. Test^, Arad. and Maggiore. PI. G6, figs. 60, 61. 



Somewhat solid, transparent, whitish, with distant thin plicae, 

 vanishing towards the base, subcancellated by less elevated, distant, 

 spiral lirse; whorls 6, somewhat convex, with deep suture; aperture 

 effuse below, lip acute, smooth within, externally varicose. 



Length, 3-4 mill. 



Norway to Mediterranean; deep sea. 



R. abyssicola, Var. coniformis, and M- asjperula, Brugn. are 

 synonyms. 



Var. ABYSSICOLA, Jeffreys. Fig. 61. 

 Shorter, sculpture less distinct. 



R. suBSOLUTA, Aradas. PL (S'o, fig. 62. 



Somewhat solid, Avhite or brownish, opaline, thinly, rather numer- 

 ously longitudinally costulate, riblets vanishing on lower part of body 

 whorl, with less prominent, close, spiral stride, stronger at the base; 

 whorls 5, convex, with deep suture; aperture exj^anded below, 

 externally varicose. Length, 2 mill. 



Europe, abj^ssal. 



It is R. elegantissima, and Var. major, Seguenza, R. abyssicola, 

 Var. obtusa, Jeffreys, and R. abyssicola, Sars. 



TJnfigured doubtful and sjnirious species described as Rissoce. 



R. PULCHELLA, R. LINEATA, R. LaYARDI, R. APPROXIMATA, R. 

 DUBIA, R. DiEMENENSIS, R. BICOLOR, and R. BADIA, Pcttei'd. 



Tasmania. 

 R. Agnewi, Tenison Woods. Tasmania. 



R. GRACILIS, A. Ad. Suez. 



R. (Goniostoma) procera, A. Ad. Giilf of Pechili, China. 



R. (Goniostoma) pupiformis, A. Ad. Japan. 



The section Gomiostoma has neither been described nor figured. 

 R. Papuana, Tapparone-CVvnefri. " Papuan Is. 



R. BELLA, R. ELEGANs, A. Ad. Philippines. 



R. ARATA, R. RUFA, R. soLiDULA, Phil. Guinea, W. Africa. 



R. UMBILICATA, Phil. China. 



