Fossil Terebratulse. 437 



20. Terehratula deltoidea, Val. in Lamk. PL XIII. fig. 20. 



T, testa compressa, transversim dilatata, triangulari, Isevi, margine 

 supero recto in medio sinuato. 



Obs, This species was jSrst figured and described by Fabio 

 Colonna (1616) under the name of Anomya diphya^ which name 

 must be preserved. It subsequently received the following names : 

 Terehratula triquetra in 1811 from Parkinson, Ter. deltoidea in 

 1819 from Lamarck, and Ter, Antinomy^ from Sig. CatuUo. It 

 is only within the last few years that geologists are agreed as to 

 its geological position, which is the middle Jurassic beds or Ter- 

 rain Callovien of M. D^Orbigny (Italy and Porte-de-France near 

 Grenoble) : it differs from a similarly shaped shell described under 

 the name of Terehratula diphya by M. le Baron D^Hombre Fir- 

 mas, said to be from the Neocomian beds of Gigondas ; and sub- 

 sequently distinguished and figured by M. D^Orbigny under the 

 name of Terehratula diphoides, ^ Pal. Fran9. Ter. Cretaces,' vol. iv. 

 p. 87. pi. 509. The specimen in B. Delessert's collection be- 

 longs to the Ter. diphya, and would appear to have come from 

 Italy. Figures are given in the ' Encycl. Methodique/ This 

 species has also received several other names. 



21. Terehratula Triangulus, Val. in Lamk. PI. XIII. fig. 21. 



T. testa longitudinaliter elongata, triangulari, Isevi : valva inferiore in 

 superiorem reflexa, ad marginem sulco impresso. 



Obs. M. D'Orbigny in his ' Prodrome ' adopts the name Te- 

 rehratula triquetra, Parkinson, ' Organic Remains,' vol. iii. pi. 16. 

 fig. 8 (1811), a name given likewise by that author to Terehratula 

 diphya, and both belong to the same beds and localities. Sub- 

 sequently Sig. Catullo named it Terehratula mutica, but which, 

 with Lamarck's, must be added to the synonyms. 



22. Terehratula Cor, Val. in Lamk. PI. XV. fig. 22. 



T. testa cordiformi subglobosa, sinu valde exarata, striis tenerrimis 

 decussatis. 



Obs. No reference to figure, locality or age is given by La- 

 marck, so that much doubt rested on this species until M. Valen- 

 ciennes found in the collection of the Garden of Plants the type 

 specimen, which he forwarded to me, and of which an exact figure 

 will be found in Plate XV. As will be seen at once, this species 

 is the same as M. Valenciennes' and Lamarck's Terehratula nU' 

 mismalis, No. 17. One of the two must be placed among the 

 synonyms ; the specimen which served as the type has exactly 

 the form of a heart, but this is only an accidental shape of the 

 species. It belongs to the lias, and is abundantly found at Vieux 

 Pont in Normandy, and in many other places. 



