ii8 Records of the Indian MnsciDH. [Vol. XXII, 



Var. dclicatula (Preston). 

 Plate XV, figs. 9, lo. 



n,i6. Velorita delicatula. Preston. Rec. hid. Mas. XII. p. 37, tiy--. 13. 

 13(7, b. 



Preston described his new species from a series of four very 

 young shells, one of these he designated as the type of his new 

 species and the others as the co-types. The Indian Museum has 

 since received many adult shells from Travancore, all of which 

 show the distinctive characters of the young shells. As a result 

 of the study of this large collection I do not think that Preston's 

 species can be considered as distinct from T'. cyprinoides, though 

 it must be designated as a distinct variety. The name delicatula, 

 however, is unfortunate, since the full-grown shells are no more 

 delicate than those of the forum typica, some indeed are even 

 thicker and stouter. 



The main distinguishing characters of this variety are the 

 more triangular shape of the shells due to a great elongation in 

 the antero-posterior axis and a corresponding shortening in alti- 

 tude, the greatly produced posterior angle due to the posterior side 

 being much longer, sloping rapidly backwards and meeting the 

 distinctly rostrate lower margin in an angularly rounded point. 

 The umbones though very oblique in the young shells are less .so 

 in adults and the lunule becomes more marked while the liga- 

 ment becomes comparatively shorter. The hinge differs from 

 that of the typical form in having all the teeth more delicate and 

 much sharper, the laterals more slanting and the posterior laterals 

 more elongate. 



Geographical Distribution. — The type-series of young shells 

 was collected in Cochin, in backwater near Ernakulam, while the 

 adult shells are all from backwaters in Travancore. A full grown 

 shell measures 32-2 mm. in length, 26 mm in height and 20*5 mm. 

 in maximum thickness. 



The soft parts are identical with those of the typical form. 



Villorita cornucopia, sp. nov. 



Plate XV, figs. II— 14. 



The shell of this species is large, subovoidal, very high and 

 comparatively narrow, with a very prominent umbonal region ; 

 dark brown to black ; both valves sculptured in the umbonal 

 region with coarse concentric ridges, which become obsolete lower 

 down, and are represented by the lines of growth only ; part of 

 the inwardly curved region of the umbones eroded ; umbones 

 solid, comparatively broad and high, retroverted inwards and 

 somewhat to the anterior side : dorsal margin broadly arched, but 

 the greater part of it hidden behind the prominent umbones ; 

 anterior margin comparatively long and regularly curved, a little 

 below the middle the curve becomes very sharp and is continued 



