132 AMERICAN JOURNAL 



Type. Magas pumila, Sby., fig. 15 a, b. 



Magas pumila, Sby., Min. Conch, ii, p. 40, pi. 119, fig. 1 to 5, 

 1818. Bouchard and Pav., Bull. See. Geol. de France 

 2nd. ser. v, p. 139, pi. ii, fig. 1 to 11. Dav., An. Nat. 

 Hist. V, pi. XV, fig. 2. Quenst., Handb. p. 476, pi. 

 xxxviii, fig. 15. 



3Iagas truncata, Rose, in Woodw. Geol. Norfolk, pi. 6, fig. 9. 



S:;S1, |woo.w.,Synopt. Tab. p. 22, fide Gray. 



Terehratula concava, Lara. An. s. Vert, vi, p. 251, No. 26, 

 (1819). Dav., An. Nat. Hist, v, 1850, June. Deshayes, 

 Lam. Ed. 2d, vii, No. 26. 

 Terehratula magas, Blainv., Man. Mai. p. 512, pi. 54, fig. 1 



(1825). 

 Terehratula pumila, v. Buch., Mem. Soc. Gdol. de France, 



iii, 1st series, p. 216, pi. 19, fig. 5. 

 Magas pumila, Gray, B. M. Cat. p. 99, fig. 9, 10. Woodw., 

 Rec. and Foss. sh. p. 217, fig. 117. Chenu, Man. de 

 Conchyl. ii, p. 207, fig. 1059, 1060. King, Permian 

 Foss. p. 81. 

 Hah. Fossil in the cretaceous beds of Europe. 

 In this, the type of the genus, the hsemal valve is almost flat 

 and the neural valve inflated and nearly touched by the apex of 

 the septum. The beak of the neural valve is strongly recurved, 

 with a minute foramen and rudimentary deltidium. The car- 

 dinal process is prominent and the area of the neural valve is 

 well defined. Although only found in a fossil state, many of 

 the specimens retain radiating colored bands. 



Magas Davidsoni, De Kon. 



Rhyncliora Davidsoni, De Koninck, fide Dav. An. Nat. Hist. 

 1855, p. 434, pi. X, fig. 4, 4a. 



Hah. Fossil in the cretaceous beds of Mrestricht. 



This species is said by ]Mr. Davidson to be similar to one of 

 Dalman's types (i?. spathulata) and the examination of the in- 

 ternal structure by M. Bosquet, during his work on the creta- 

 ceous Brachiopoda of Maestricht, shows that it is a typical 

 Magas. The apophyses exactly resemble those of M. pumila, 

 while the hinge margin is much broader than in that species, 

 and nearly straight. The other type of Rhyncliora was Wald- 

 heiinia? pectinata, Linn., according to Woodward and Dr. Gray. 

 Tliis disposes of a genus badly cliaracterized and i'ounded on an 

 error, Avhich has been the cause of much difiiculty and confusion. 

 (See Woodw. Man. Rec. and Foss. Shells, p. 217, note). 



