A. NEW SPECIES OF ACMMA FROM BOMBAY. 689 



■dispositi, radio fusco intermedio quam cseteris pallidiori divisi; facies 

 interna alba, area central! pallide olivaceo-fusca, limbo definite albo et 

 nifo-fusco notato, hand crenulato. Long. 17"5, diam. 15, alt. 6*5 mm.* 



About the same form as the Bombay Patella aster, but dift'ering in other 

 respects. Acmoea parasitica (d'Orbigny) is a little like the present species, 

 ■but rather more ovate, and " arched in every direction in consequence of 

 -attaching itself to other shells " with convex surfaces. On the contrary 

 all the specimens I have seen of A. Bombayana appear to have rested upon 

 flat or almost level surfaces, as the margin is even and unarched all round. 



The rays are generally of two shades of brown, some much darker than 

 others, and the paler ones nearly always falling between the white rays, 

 which frequently appear to be in pairs. In addition to the rays a fine 

 brown and white reticulation not infrequently occurs. The fine radiating 

 thread-like lines are only observable in well-preserved specimens. The 

 interior is thickened with a white callus deposit, excepting the central 

 portion, which is stained a pale livid olive and defined from the white 

 part of the interior by a distinct horseshoe-shaped margin. The outer 

 limbus is thin, sharply defined, and prettily marked with the ends of the 

 brown and white rays. 



Var. Ceylanica. Fig. D. 



Like the type, but a trifle more elevated, without the tine brown reticula- 

 tion, but with the darker rays commencing as spots or dots near the apex. 

 Largest specimen 19*5 mm. in length, 16 in diameter, and 9 high. 



ifa6.— Galle, Ceylon (H. P. Blanford). 



The increased elevation of this variety is probably due to its occurrence 

 in a more exposed position than the Bombay shells. It has been observed 

 with regard to our common limpet, Patella vulgata, that specimens occur- 

 ring near high-water mark, and consequently more exposed to the break- 

 ing of the waves, are higher and more conical than those found lower 

 down on the shore. 



The Aonoea Travancorica, Preston, has an arched lateral basal margin, is 

 difi"erently coloured ( ** pale brownish yellow with occasional blotches of 

 dark purple ") , and more roughly sculptured. The colour of the interior 

 ©f the shell is not described, but it is merely said to be iridescent. The 

 margin is described as " regularly spotted with purple." This iridescence 

 *nd the apparent absence of a defined limbus or border seem to indicate 

 that this species has more aflinity to the Patellidse than the Acmseidse. 



An average specimen. The shell figured is 22 mm. in length, 19 high and 



7 in height. 

 43 



