700 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127 
Genus INGRIA 6pik, 1930 
Plate 163, B, figures 7-20 
Ingria Optx, Brachiopoda Protremata der estlandischen Ordovizischen Kukruse-Stufe, Acta 
et Comment. Univ. Tartu, ser. A, vol. 17, No. 1, p. 57, 1930; idem, ser. A, vol. 23, No. 3, 
PP. 13-17, 1932.—ULrRicH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 185, 1938. 
Palinorthis UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 625, 1936. 
In 1936 Ulrich and Cooper proposed the genus Palinorthis for an unusual 
species from the Ordovician east of Frenchman Flat, Las Vegas (1°) Quad- 
rangle, in southern Nevada, with genotype P. cloudi. This genus later proved 
to be a synonym of Opik’s genus Ingria. In 1939 Bridge and Cooper collected 
additional material of Ingria cloudi. After being etched from the limestone the 
specimens constitute an excellent series. The species proves to be a variable 
one, but the variations include even minor details shown by Opik’s specimens 
from Rog6o Island. 
As revealed by the Nevada examples /ngria possesses the peculiar double 
tooth so prominent in Palaeostrophomena. It also has a few accessory denticles 
on the hinge margin on each side of the tooth. Some specimens show an unusu- 
ally large development of the adustor scars. Most of the specimens have the beak 
filled with adventitious shell deposited under the pseudodeltidium and welding 
that structure to the apex. Considerable variation occurs in the cardinal process ; 
it varies from slender to moderately thick but retains its septumlike character in 
all the specimens. In the pedicle valve the thickening anterior to the adductor 
scars varies from a slender ridge to a wide triangular or somewhat rhomboidal 
patch. 
This genus so far has been found in the United States only at the Frenchman 
Flat locality. 
Types.—Figured hypotypes: 117559b-g,j; unfigured hypotypes: 117559a,h,ji. 
Family LEPTESTIIDAE Opik, 1933 
Plectambonitidae with shells of normal and reversed convexity, having a promi- 
nent median ridge or septum. Cardinal process trilobed and chilidium narrowly 
elevated. 
Subfamily LeptestimnAE Opik, 1933 
Leptestiidae with prominent median septum. 
Genus PALAEOSTROPHOMENA Holtedahl, 1916 (emend. Spik, 1933) 
Palaeostrophomena HortepAut, Vidensk. Skrift., I, Mat.-Nat. 1915, No. 12, p. 43, 1916; 
emended, Opik, Acta et Comment. Univ. Tartu, ser. A, vol. 24, p. 24, 1033. 
Holtedahl named Strophomena concava F. Schmidt as type of his new genus. 
Later work by Opik, however, showed that the named type and the Norwegian 
specimens figured by Holtedahl are not congeneric. Opik therefore proposed 
the genus Jnversella for the S. concava of Holtedahl (not Schmidt) and emended 
Palaesotrophomena on the basis of a study of Schmidt’s type specimens of 
S. concava. 
