NO. 2 BRACHIOPOD SUPERFAMILY STENOSCISMATACEA — GRANT 69 



Table 11. — Measurements of Camerisma girtyi from the Mississippian of Alaska 



Measurements, in millimeters 



USNM No. Length Width 



142069 16.7 22.0 



142070 c.19.0 c.23.0 



142071 20.0 20.0 



and in its bilateral symmetry. It is larger than the Permian species C. 

 sagmaria n. sp. and has fewer costae. It is somewhat smaller than 

 C. ? pentameroides (Tschernyschev) from the Permian of Russia, and 

 its fold is higher and slightly sharper at the crest. However, Mississip- 

 pian C. prava and Permian C. f pentameroides are so similar that from 

 external appearances it is difficult to doubt that they are congeneric. 

 C. girtyi is narrower, more globose, and has a broader, more gently 

 arched fold and shallower sulcus than C. ? sella (Kutorga) from the 

 Russian Permian. 



Discussion. — This species is based on three well-preserved speci- 

 mens which are described, despite the small number, because they add 

 importantly to the concept of the rare genus Camerisma, and because it 

 is not likely that additional specimens will be collected soon. 



Occurrence and abundance. — Unnamed Upper Mississippian lime- 

 stone of Condon (1961), Craig Quadrangle, Southeastern Alaska, all 

 specimens collected by G. H. Girty in 1918: U.S.G.S. loc. 3708, south 

 shore of island No. 85 in Ladrones Islands, one specimen (USNM 

 142071) ; U.S.G.S. loc. 3684, massive white limestone at north point 

 of island No. 250 in Ladrones Islands, two specimens (USNM 

 142069-70). 



CAMERISMA SAGMARIA Grant n. sp. 



Plate 8, figs. 2-2a ; figure 13 



Camerophoria sella (Kutorga) SCHELLWEIN, E., 1900, Abhand. Geol. Reichs- 

 anstalt, Wien, vol. 16, pt. 1, p. 99, pi. 15, figs. 1-4. 



Shell about medium size, strongly biconvex; outline transversely 

 subpentagonal ; anterior commissure strongly uniplicate, with high 

 vaulted fold in shape of Gothic arch, not standing strongly above flanks, 

 but greatly increasing convexity of valve ; sulcus shallow, broad, nar- 

 rowing anteriorly to form tongue extending into arch of fold ; costae 

 low, rounded, confined to fold and sulcus, beginning about 5 mm. ante- 

 rior to beaks, numbering up to five on fold, one fewer in sulcus, in- 

 creasing anteriorly by bifurcation (median costa formed by crest of 

 fold, not bifurcating) ; concentric ornament weak, consisting of fine 

 growth lines and widely spaced laminae. 



Pedical valve thick in umbonal region ; beak curved, apparently 



