Prof. E. Forbes on Fossil Invertebrata from Southern India. 155 



Lower valve with beak 3 inches long. Breadth 2| inches. Thickness 2| inches. Upper 

 valve 2i inches in length. 



This fine species has the smaller valve very regularly eared. The sculpture of 

 the surface is regular, and varied by a few arched scales placed at irregular distances 

 towards the margin. There are traces of decussating striae between the ribs. The 

 beak is triangular. It is nearly allied to the Neocomian Spondylus Rdemeri, 

 described by Deshayes. 



Locality, Pondicherry. 



2. Spondylus calcaratus, sp. nov. PI. XVIII. fig. 2. 



S. testa ovata, obliqua, valva dextra affixa, ad umbonem rostrata, longltudinaliter striata, 

 transverse phcata; valva sinistra convexa, longitudinaliter sulcato-striata (interstitiis rotundatis), 

 obsolete nodulosa. 



The largest specimen measures 4 inches, without beak, in length. A middle-sized individual 

 has the following proportions. Length of upper valve 3j\ inches ; of lower valve with its 

 beak 4 inches. Breadth of either valve 3| inches. Length of beak 0| inch. Breadth about 

 1~ inch. Thickness 1| inch. 



Very nearly allied to the last, but presenting differences which induce me to 

 regard it as specifically distinct. The large and differently formed beak, the 

 rounded instead of sharp ribs, and the nodulose surface serve to distinguish it. 

 ■ Locality, Pondicherry. 



Genus Plicatula, Lamarck. 



1. Plicatula septemcostata, sp. nov. PI, XVIII. fig. 4, 



P. testa subobliqua, suborbiculari, convexiuscula, inaequivalvi, longitudinaliter costata, costis 

 septem majoribus, subangulatis (subsquamosis) ; apice affixa. 



Length \^^ inch. Breadth ly'l^ inch. Thickness of united valves Oj^ inch. 



A nearly orbicular, slightly oblique shell, depressed and inequi valve. The 

 surface is ribbed longitudinally ; seven of the ribs rise prominently and angularly. 

 The nearest allies of this species are oolitic. 



Locality, Pondicherry. 



2. Plicatula multicostata, sp. nov. PI. XVIII. fig. 3. 



P. testa ovata, depressa, longitudinaliter costata, costis numerosis, alternatis minoribus 

 abbreviatis. 



Length Oy'g inch. 



A species allied to some cretaceous forms, and well-marked by the peculiar 

 arrangements of the numerous ribs, which are alternately larger and smaller, the 

 smaller ones stopping short. 



Locality, Verdachellum. 



