of the Piedmontese Coast. 183 



referred to in these words, " variat cingulis transversis in carinas 

 acutas elevatis ; " but it does not correspond with his description and 

 figure of the typical species. In the last and penultimate whorls 

 there are two rows, and in the preceding whorl one row of tubercles. 

 Foci, near Genoa, on sea- weed in the littoral zone ; not common. 

 Nice, Verany. 



Rissoa costata, B. M. (R. exigua, Ph,). 



Rissoa contorta, n. s. PL II. f. 6, 7. 



Testa brevi-cylindrica, ad apicem obtusa, lutea aut alba, solidula ; 

 anfractibus 4, ventricosis, sensim crescentibus, leevibus, nitidis, 

 zonis duabus fulvis cinctis; sutura profunda; apertura subrotunda, 

 subeiFusa, tertiam spirae partem superante, margine connexo, 

 soluto ; umbihco angusto ; long, -^^y lat. 3^ unciae. 



Genoa, Foci, Sestri di Levante and Spezia, on sea-weed in the 

 littoral zone ; common. Nice, Verany. 



This elegant species appears to be the representative of our Rissoa 

 striata ; but it has a different habitat, the latter being found under 

 stones and at the roots of Corallina officinalis in the sublittoral zone. 



Rissoa glabrata, Ph, ; and var. alba ; (R. punctulum, Ph., Moll. Sic. 

 vol. i. p. 154). Not the species referred to with doubt by the authors 

 of the * British Mollusca' under the name of Odostomia glabrata, but 

 allied to R. vitrea, from which it differs in the greater solidity of the 

 shell, its more obtuse whorls, and more contracted aperture which is 

 strengthened by an outer rib. It varies considerably in size. I found 

 it in abundance on all the coast, and noticed it in M. Verany' s collec- 

 tion from Nice. — R. vitrea, B. M. — R. proxima, B. M. — R. incon- 

 spicua, B. M. (R. rudis. Ph.) ; var. a. albula, B. M. (R. nana, Ph.) ; 

 var. c, B. M. (R. radiata, PA.) ; var. c?, B. M. ; var. (R. granulum. 

 Ph.). — R. semistriata, B. M. (R. subsulcata. Ph.). — R. pulcherrima, 

 B. M. Some older and more produced specimens agree better with 

 Philippi's description and figures of R. soluta than the species de- 

 scribed under that name in the * British Mollusca,' but they want the 

 peculiar markings of R. pulcherrima. — R. fulgida, B. M. — R. parva, 

 B. M. It is remarkable that Philippi did not notice the typical form, 

 and that the other and more common form (interrupta) did not occur 

 to me among so many thousands of Mediterranean Rissoae. — R. sim- 

 plexy Ph. ; probably a variety of the last ; var. (R. pulchella. Ph.) : 

 this has some analogy with R. inconspicua in respect of markings, 

 but differs in the form of the spire and apex. — R. violacea. Ph. — R. 

 ventricosa. Ph. (R. rufilabrum, B. M.). — R. oblonga. Ph. (R. costu- 

 lata, B. M.) ; var. (R. similis. Ph.) ; and var. minor. — R. variabilis, 

 V. Miihlfeld (R. costata, Ph). The name of costata given to this 

 species by Desmarest must be relinquished, as it was long previously 

 used by Adams for the R. exigua of Michaud ; var. : this somewhat 

 resembles R. labiosa in form, but the texture, colour and markings 

 are different. — R. labiosa, B. M. (R. elata. Ph.). — R. auriscalpium. 

 Ph. — R. monodonta. Ph. — R. thermalis,(im/J.) Ph. ; var. minor (R. 



