22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I39 



in the U. S. National Museum collection are from 650 to 2,200 

 fathoms. The Australian species is a shallow-water form found in 100 

 fathoms. Cryptopora boettgeri from off Agulhas Bank, South Africa, 

 is from deeper water, 500 meters (275 fathoms). 



CRYPTOPORA GNOMON Jeffreys 

 Plates 5, C, 21, D 



Crytopora gnomon Jeffreys, Nature, vol. 1, Dec. 2, p. 136, 1869. 



Atretia gnomon Jeffreys, Proc. Roy. Soc., vol. 18, No. 121, p. 421, 1870; David- 

 son, Trans. Linnaean Soc, ser. 2, vol. 4, pt. 2, p. 173, pi. 25, figs. 6-13, 1887. 



Neatrctia gnomon (Jeffreys) Fischer and Oehlert, Exped. Sci. Travailleur et 

 Talisman, p. 122, figs, na-c, 1891. 



This is a deep-water form that differs markedly from C. rectimar- 

 ginata in its nonalate deltidial plates, more strongly folded anterior 

 commissure, and other details. Figures are introduced for comparison 

 with the Florida species. 



Types. — Figured specimens U.S.N.M. 94367, 44911a, c, d. 



Horizon and locality. — Recent, 780 fathoms, off Cuba; 1,525 

 fathoms at U. S. Fish Commission Station 2221, south of Marthas 

 Vineyard, Mass. 



Genus MANNIA Davidson, 1874 



Plates 1, A, 21, F; text figure 1, B 



Mannia Dewalqne, Prodrome d'une Description Geol. Belg., p. 432, 1868 (not 

 described or figured) ; Davidson, Geol. Mag., dec. 2, vol. 1, No. 4, p. 156 

 (extract p. 6), 1874(b) ; Thomson, New Zealand Board Sci. Art, Manual 7, 

 p. 296, 1927. 



This interesting little brachiopod [type species (by monotypy), 

 Mannia nysti Davidson, 1874] was described by Davidson who indi- 

 cates that some points of its anatomy are still to be learned. The 

 affinities of Mannia, as well as its anatomy, are not clearly under- 

 stood because some workers have regarded it as a rhynchonelloid but 

 one of the best informed students of brachiopods, J. Allan Thomson, 

 thought that it is a terebratuloid. Its rhynchonelloid affinities, how- 

 ever, now seem clear and unquestionable. Because of the rarity of this 

 species little is known of it but restudy of a good specimen and photo- 

 graphs of the types now make its features clear. 



According to Davidson's description, Mannia is similar to Crypto- 

 pora externally as well as internally. The beak region is elongated 

 and pointed and the pedicle opening is elongate triangular. The pedicle 

 opening is bordered by attenuated, triangular deltidial plates as in 



