42 ACMvEA. 



Figs. 69, 70 are copies of Reeve's illustrations of his cubensis ; figs. 

 56, 57 are melanoleuca Rv. not Gmel. ; figs. 58, 59, 60 are drawn 

 from a large specimen of typical cubensis. 



Var. SIMPLEX Pilsbry. PI. 4, figs. 63, 64, 65, 66, 67, 68. 



Shell having a tendency to be squarely orbicular when fully 

 adult, and much elevated, the black lines continuous, separate, 

 rarely splitting more than once. This is the P. leucopleura of Rv., 

 not Grn. nor Lam. Specimens from the Bahamas were collected 

 from the shells of Livona pica ; figures 66, 67, 68 were drawn from 

 one of these. Fig. 63 represents a large specimen of the typical 

 form of simplex. 



Another modification of either the cubensis or the leucopleura 

 stock is figured on pi. 4, figs. 61, 62. It is small, conical, apex 

 erect and subcentral. When cleared of the extraneous calcareous 

 coating it is seen to be either smooth or obsoletely ribbed, the ribs 

 narrow, separated ; marked with blackish-brown radiating blotches 

 which split into two or three branches toward the basal margin. 

 Inside with a dark central area with or without a white central 

 spot, the border black spotted with white. The external color- 

 markings may be faintly seen inside. The exact status and Affini- 

 ties of this form are somewhat doubtful. It is abundant at Man- 

 cheoniel and Port Antonio, Jamaica. 



The locality " West Indies" given in the books for Subemarginula, 

 notata L. is probably owing to a confusion of that species with these 

 similar AcmaBas. Specimens of notata marked " Ceylon " are before 

 me, and I have no doubt that it is an oriental species. The very 

 strongly inflexed ends of the muscle-scar, and the slight trace of a 

 groove between the apex of the cavity and the front margin will 

 enable one to separate S. notata from all Docoglossate limpets. 



A. ONYCHINA Gould. PI. 34, figs. 22, 23, 24. 



Shell small, thin, irregular, depressed, broadly ovate, with twenty 

 or more obsolete, unequal ribs. The general color is ashy green, 

 with deep olive stripes between the ribs. Besides this, the whole 

 surface is marked with fine radiating striae, and by crowded loose 

 lines of growth, giving the surface a decomposing aspect. Margin 

 sharp, irregular ; interior mottled with cream-color and clear 

 chestnut-brown ; central spatula thick and well marked ; a marginal 

 border is striped alternately chestnut and yellow, answering to the, 



