358 ^Ir. J. S. Gaskoin on the genus Pachybathron, 



fun-ows ; spire flat, depressed (in young individuals apex slightly 

 prominent and obtuse), volutions 3-4-, more or less crenulated ; 

 base rather round, broad and very thick, abrupt at its outer edge, 

 covering the anterior third of the side of the shell, and diminish- 

 ing in width terminates on the dorsum of the channel ; aperture 

 rather narrow, slightly curved, not rostrated posteriorly; lip 

 thick, denticulated on its inner edge the entire length ; colu- 

 mellar side has 12-13 strong, rather distant, linear denticula- 

 tions extending from the outer margin of, and over the base, to 

 the inner edge of the columellar groove ; columellar groove broad 

 and shallow ; extremities obtuse and thick ; channel short. 



Long -j%^o, wide y^f^ of an inch. 



Hab. West Indies. Cab. Gaskoin. 



Plate XII. figs. 4, 5, 6, thrice nat. size. 



Marginella albina. 



Testa ohlougo-ovata, coniformis, opaca albicans; plerumque 

 plus minusve postice coronata nonnunquam fortiter seu laevis- 

 sime ; spira brevi, subobtusa, anfractibus quatuor ; apertura 

 latiuscula, recta ; labio externo crasso, lajvi, edcntulo; margine 

 externo albo, prominente ; labio interno Isevi, antice dentibus 

 quatuor prominentibus, postico tenui, distincto, ad aperturam 

 subrectangulo ; canali nuUo. 



Long. T-VV, lat. T%% poll. 



Hab. in Australia. Mus. Gaskoin, Brit. Mus. 



Shell oblong-ovate, somewhat conifonn, opake-whitish colour, 

 or of a light orange tint, the shoulder generally more or less 

 coronated, often strongly ; spire short, rather obtuse, volutions 

 four ; aperture moderately wide and straight ; outer lip thick, 

 smooth, edentulous ; external margin white, strong and promi- 

 nent, continuing on the edge of the dorsum forms the anterior 

 plait ; inner lip smooth, on the anterior portion four projecting 

 teeth, the posterior thin and isolated, standing nearly at right 

 angles with the aperture, the others white and parallel with the 

 termination of the margin ; channel none. 



Long T^o^^y, wide ^^.e. of an inch. 



Hab. N.VV. Australia. Cab. Gaskoin, Brit. Mus. 



Plate XII. figs. 7, 8, twice and half larger than nat. size. 



Marginella Albanyana. 



Testa subcyhndrica, tenui, Isevi, nitida, pallidissime fulva, an- 

 fractu viltimo subtilissime striato ; basi rotundata ; apertura rec- 

 tiuscula, angustiuscula, antice subexpansa ; columella in medio 

 subventricosa, antice rapide attenuata, subfornicata, oblique qua- 



