PLATE XXIII. 



Fig. ... 1. Myoconcua SUBOVATA, (S/o/., p. 362 ; Koloiure, TrlcMnopolij (jronp. 



Figs. 2, 3, & 5. Mytiltjs Aemaloorensis, Stol., p. 381 ; ComarapoUiam, Arrialoor group. 



Figs. 4, C, & 7. MoDiOLA radiatula, Stol., p. 379; fig. G is enlarged to three times the natural 

 size ; ComarapoUiam, Arrialoor group. 



Figs. 8 — 9. Modiola annectans, SloL, p. 380 ; Vijlapnudij, Arrialoor group. 



Figs. 10 — 11. Modiola polygona, d'Orh., p. 378; 10, 10 a, side-, and umhonal-, views; typical 

 form; 11, 11«, side-, and front-, views of a somewhat more elongated speci- 

 men ; Pondicheny, ? Valudayur group. 



Figs. 12 — 13. Modiola TYFiCA, Forh., p. 377; 12, represents Forbes' original J/^/«7?w e^y/jrw; 

 the other sjiccimeus are from Anapaiuli/, Trichinopoly group. 



Fig, ... 10. LiTiioDOMUS [BoTUL.\] TUMiDULA, 5/o/., p. 375; (compare pi. xxxviii, fig. 13) ; 



soulh-catsi of Arrialoor, Arrialoor groap. 



Fig. ... 17. LiTHODOMUS CuRTA, Stol., p. 376; enlarged twice the natural size; Odium, 



Ooiatoor group. 



Figs. IS — 19. LiTHODOMUS SUBCYLINDRICA, Slol., p. 370; a Sorter and an elongated variety; 

 both eularged twice the natural size ; Odium, Ootaloor grovp. 



