196 CUETACEOUS PELEOYPODA 



is a Ceromya (see p. 78). However, of tlie five species wbicli I have to mention only four are 

 sufficiently well preserved to admit of a reliable determination,, Veniella ( Venilicardia) oltruncata, 

 Gyprina Forhesiana and cristata, and Cyprina (Cicatrea) cordialis ; one species apparently belong- 

 ing to Trapezium is only known from a single imperfect valve ; until better specimens have been 

 discovered it would be useless to burden our literature with names which cannot have any value 

 either for the geologist or palaeontologist^ but would only remain a puzzle to the conchologist. 



Thus, looking at the family Glossib^, as represented in cretaceous rocks, we 

 find a great number of well defined species belonging to Veniella, one or two may 

 be Glossocardice and a few belong to Cyprina proper, and its sub-genus Cicatrea, 

 Of Glossus itself not one species is known with certainty, but that form of shell 

 does occur. Eew species also externally resemble Trapezium, but none is sufficiently 

 certainly known by its hinge. Apricardia is as yet entirely cretaceous and so is 

 Cicatrea, but both are likely to occur in other formations also, the first most 

 probably in the tertiaries, the last in the upper jurassics. 



TRAPEZIUM, 3Ieg, v. Millilf,, 1811, (vide p. 186). 

 >y ? Teafezium, sp. ind., PI. XIII, Pig. 4. 



A trapezoid, or almost quadrangular left valve, moderately inflated, with a pro- 

 minent sub-obtuse beak ; the region between it and the postero-inferior end is 

 the highest, and from it the shell slopes very gradually on either side, the supero- 

 posterior and antero-inferior extremities being mostly extended; the surface is 

 covered with minute radiating striae and a few distant concentric grooves, indicating 

 stages of growth. Hinge-teeth unknown. 



The remarkably quadrangular form of this species and the moderate thickness 

 of its shell make it probable that the species belongs to Trapezium, but it was 

 impossible to trace the hinge-teeth in the only figured right valve known. 



Locality. — North of Serdamungalum, in a yellowish highly calcareous conglo- 

 meratic sandstone. 



Formation, — Trichinopoly group. 



VENIELL2V, Stol., 1870, (vide p. 189). 



^ Veniella [Venilicardia] obtruncata, Stoliczka, PI. VIII, Pigs. 4-7. 



Ven, testa siib-quadrangulari, valde inflata, crassa ; umbonibus incurvis, approxi- 

 matis, obtusiusculis ; lunula moderate excavata, sub-rotundata, latiuscula, linea impressa 

 marginata, area longa angusta, sub-profunda, et nymphis crassissimis instructa ; valvis 

 in regione ab umbonibus ad terminationem postero-inferiorem extensa maxime elevatis, 

 ab ea elevatione antice versus gradatim et convexiuscule-, postice rapide-declivi ; 

 superficie striis concentricis tenuihus ac nonnullis crassioribus notata ; car do in valva 

 dextra dente longo postico indistincte bijido, curvato, oblique descendente ac altero 

 aniico liorizontaliter extensor incequaliter diviso^ postice maxime elevato, in valva 



