388 



BRACHIOPODA. 



[WHI. ZYG, 



plate ; one tooth on each side of the 

 deltidium, supported by plates, and 

 fitting in the sockets of the dorsal 

 valve ; structure punctate. Type W. 

 australis. 



maria, Hall, 1863, (Meristellamaria,) Trans 

 Alb. Inst., vol. 4, p. 212, Niagara Gr. 



FIG. 637. Waldheimia australis. Dorsal valve' 

 .7, cardinal process; t, dental sockets; p, hinge 

 plate : *, septum : c, crura of the loop ; I, re- 

 flected portion of the loop ; m, quadruple 

 adductor impression. Ventral valve ; /, fora- 

 men; d, deltidiumj; I, teeth; a, single adductor 

 impression ; r, cardinal muscle ; x, accessory 

 muscles; p, pedicle muscles; v, position of the 

 vent; 2, attachment of pedicle sheath. 



compacta, White & St. John, 1868, Trans. 

 Chi. Acad. Sci., p. 119, Up. Coal Meas. 

 deweyi, see Retzia deweyi. 

 formosa, see Retzia formosa. 

 globosa, see Trematospira 



globosa. 

 rectirostra, see Trematospira 



rectirostra. 



WHITFIELDIA, Davidson, 1 881 , 

 Lond. Geo. Mag., vol. 8, 

 p. 289. [Ety. proper 

 name.] While Meris- 

 tella is distinguished 

 from Merista by having 

 no shoe-lifter process ; Whitfieldia is dis- 

 tinguished from both by the absence 

 of those peculiar ring-shaped processes 

 attached to the loop, and has instead 

 only a short, bifurcating process, where 

 in Merista and Meristella the rings are 

 formed. These internal differences in 

 the spirals seem to distinguish the 

 genera. Type W. tumida. 



FIG. 638. Wald- 

 heimia aus- 

 tralis. 



FIG. 639. Whitflelda maria. Internal casts. 



ZYGOSPIKA, Hall, 1862, 15th Rep. N. Y. Mus. 



Nat. Hist., p. 126. [Ety. zygos, yoke; 



xpira, spire.] General form of Atrypa 



with internal spires having a broad 



loop passing from the outer limbs of 



the spiral band entirely across from 



side to side, near to or above the center, 



and close to the inner side of the dorsal 



valve. Type Z. modesta. 

 concentrica, Ulrich, 1879, Jour. Gin. Soc. 



Nat. Hist., vol. 2, p. 14, Hud Riv. Gr. 

 headi, Billings, 1862, (Athyris headi,) Pal. 



Foss., vol. 1, p. 147, Hud. Riv. Gr. 

 headi var. anticostiensis, Billings, 1862, 



(Athyris headi var. anticostiensis,) Pal. 



Foss., vol. 1, p. 147, Hud. Riv. Gr. 

 headi var. borealis, Billings, 1862, (Athyris 



headi var. borealis,) Pal. Foss., vol. 1, 



p. 147, Hud. Riv. Gr. 

 headi, Meek, see Glassia headi. 

 minima, Hall, 1879, Desc. New Spec. 



Foss., p. 14, and llth Rep. Geo. and 



Nat. Hist. Ind., p. 305, Niagara Gr. 

 modesta, Say, 1847, (Atrypa modesta,) 



Pal. N. Y., vol. 1, p. 141, Trenton and 



Hud. Riv. Gr. 

 modesta var. cincinnatiensis, 



Meek, 1872, Pal. Ohio, vol. 



1, p. 126, Hud. Riv. Gr. 

 pauper, Billings, 1866, Catal. 



Sil. Foss. Antic., p. 46, An- 



ticosti Gr. desta. 



subconcava, Meek & Wor- 



then, 1868, Geo. Sur. 111., vol. 3, p. 380, 



Low. Held. Gr. 



