368 RISSOIA. 



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

 tinuous. 



Suez. 

 Section ACTONIA, Monts. 1884. 



R. TESTAE, Arad. and Maggiore. PI. 66, 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 R. asperula, Brugn. are 

 synonyms. 



Var. ABYSSICOLA, Jeffreys. Fig. 61. 

 Shorter, sculpture less distinct. 



R. SUBSOLUTA, Aradas. PI. 66, fig. 62. 



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

 ously longitudinally costulate, riblets vanishing on lower part of body 

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

 whorls 5, convex, with deep suture; aperture expanded below, 

 externally varicose. Length, 2 mill. 



Europe, abyssal. 



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

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



Unfigured doubtful and spurious species described as Rissoo3. 



R. PULCHELLA, R. LINE AT A, R. LAYARDI, R. APPROXIMATA, R. 



DUBIA, R. DIEMENENSIS, R. BicoLOR, and R. BADIA, Petterd. 



Tasmania. 



R. AGNEWI, Tenison Woods. Tasmania. 



R. GRACILIS, A. Ad. Suez. 



R. (GONIOSTOMA) procera, A. Ad. Gulf of Pechili, China. 



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



The section Gomiostoma has neither been described nor figured. 

 R. PAPUANA, Tapparone-Canefri. Papuan Is. 



R. BELLA, R. ELEGANS, A. Ad. Philippines. 



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



R. UMBILICATA, Phil. China. 



