186 PLANAXHXE. 



If Mr. Smith had been able to examine as many specimens 

 as I have, he would have found that none of the characters he 

 relies on are constant ; e. g., it is not smoother than many of 

 the Persian Gulf specimens ; the sulci are of exactly the same 

 width ; and the coloration recorded is not constant. Curiously 

 the typical coloration is also exactly represented by typical 

 Persian PL breviculus. The " basal canal " likewise is often, 

 if not generally, entirely like that of its allies ! 



The habitat is very interesting, being the only one known 

 East of the Bay of Bengal : it is particularly important to find 

 the species actually living with PI. sulcatus. The fig. of PI. 

 encausticus in the Con. Iconica is very fair, but fig. 30, a " PI. 

 savignyi," has the last whorl less tumid than is usually the 



3. Planaxis breviculus. 



Planaxis breviculus, Deshayes, Mag. Zool. 1844, Hab. ?, long. 21, diam. 15 

 mil. ; Suez, "frequent," fide McAndrew. 



4 Persian Gulf; colL W. T. Blanford, Esq. [19, 13J]. 



Coloration close to that of the original figure, also to that 

 of the Arakanese PI. savignyi, var. encaustica. PL breviculus 

 is scarcely more than a well-marked variety of PL savignyi ? 

 The darker-coloured aperture, however, with obsolete liration, 

 seems to be characteristic. 



var. tessellata, nov. 



PL breviculus, var., Smith, Ann. Mag. IX, 1872, Persian Gulf. 



20 Persian Gulf; coll. W. T. Blanford, Esq. [long. 20, diam. 14], 



Both these and the preceding have a more acuminate spire 

 than in the figure of Deshayes. The figure in Con. Iconica 

 seems to me different again ; possibly it represents PI. brevis, 

 Quoy, as Sowerby quotes the latter's localities " Guam and N. 

 Guinea" for the figure in question. 



4. Planaxis planicostatus. 



Planaxis planicostatus, Sowerby, App. Tankerv. Cat. 1825, Gallapagos I. ; 

 fide Smith=Buc. planaxis, Wood ; =Pl. canaliculata, Duval, Rev. 

 Zool Cuv. 1840 ; =Pl. circinata, Lesson, Rev. Zool. Cuv. 1842, " Aca- 

 pulcoO-020." 



5 Panama -, ex c. Prof. E. C. Stearns and Asiatic Soc. Bengal [28, 16]. 



