No. 2314. LIST OF RECENT BRACHIOPODA—DALL. 281 



Type. — T. radians Defrance, Cretaceous, Maestricht. 



The synonymy of this genus has been left in a confused state by 

 authors and the tracing of citations to their source has revealed a 

 number of errors which have been extensively copied. Fischer states 

 in his Manuel, (page 1330), "Le genre TJiecidea cr6e nominalement 

 par Defrance en Ferussac, 1819, n'a 6t6 caract6ris6 qu'en 1822 dans 

 le dictionnaire classique d'histoire naturelle; le m^me ann^e, Brong- 

 niart cite comme type le TJiecidea radians. " This is not quite exact. 

 The true history of the name is as follows: 



TJiecidea occurs as a nude name in Ferussac's Tableau. Brongniart 

 in his description of the chalk of the hill of Maestricht (taken chiefly 

 from the work of Faujas de Saint Fond on that locality, published in 

 1799) cites four fossils of which the second and third are TJiecidea 

 radians and JiieroglypJiica of Defrance. There is no reference to 

 either in the text, but after the first name is a reference to Faujas' 

 figure 8 of his plate 17. This of course in conformity with modern 

 usage fixed the genus and the type. Probably in ignorance of this 

 citation, Ferussac in the Dictionnaire Classique in 1822, referred to 

 the genus, under the article Brachiopodes, only by its vernacular name 

 and as "non encore decrit" (p. 47). In this publication it is only in 

 1830, that Deshayes latinizes the name and diagnoses the genus. Also 

 Sowerby in 1823, while at Doctor Goodall's recommendation correct- 

 ing the unpublished name to TJiecidium, states that he does not name 

 the figured recent species because he *' will notinterfere with Defrance's 

 unpublished account of the genus." 



Thus it is clear that the name of Defrance circulated among his 

 colleagues and correspondents several years before it was formally 

 described and it is only by the accident of the citation of Faujas' fig- 

 ure by Brongniart, that the name is preserved in its original form. 



The TJiecidea radians Defrance, according to Bronn is a synonym of 

 Terehratulites papillatusSchloth.eiin, 1813, and was later the T. pumUa 

 of Lamarck but not of Sowerby. The type of the genus therefore is 

 TJiecidea papillata (Schlotheim) from the Cretaceous of Maestricht. 



The recent forms differ sufficiently from the fossil type to have been 

 separated as follows by Munier Chalmas. 



Subgenus Lacazella Munier Chalmas. 



Lacazella Munier Chalmas, Bull. Soci6t6 Geologique de France, ser. 3, vol. 8, 

 1880, vol. 1, p. 279, Feb., 1880 {?=Thecidium Sowerby, 1823). 



LACAZELLA MEDITERRANEA Risso. 



Thscidium (sp. not named) Sowerby, Genera of Sh., fasc. 20, fig. 6, Nov., 1823. 

 Theddea mediterranea Risso, Hist. Nat. Eur. M6rid., vol. 4, p. 394, fig. 183, 



1826.— Defrance, Diet. Sci. Nat., vol. 53, p. 434, 1828. 

 Thecidea spondylea Scacchi, Cat. Conch., p. 8, pi. 1, figs. 7-9, 1836. 

 Thecidium mediterraneum Davidson, Mon. Rec. Brach., pt. 2, p. 156, pi. 23, 



figs. 12-22, 1887. 



Type locality. — Mediterranean, near Nice. 



