PLATE XIX. 



Fig. ... 1 . Trigonoakca Telugensis, Stol., p. 352 ; north of Alundampooram, Trichtnopoly 

 group. 



Figs. 2—3. Trigonoaeca Trichinopolitensis, ¥orhes, p. 353 ; 2, a very elongated specimen 

 from north of Alundanapooram ; 3, a shorter and more quadrilateral specimen 

 from near Serdamungalum ; Trichinopoly group. 



Figs. \ — 5. Trigonoakca abrtjpta, Forbes, p. 352; 4, a small nearly perfect specimen; 

 5, oa, internal and umbonal views of a large specimen ; in fig. 5 the posterior part 

 of the hinge has been completed from the other specimen; both from near 

 Serdamungalum, Trlcliimpoly group. 



