NO. 10 CAMBRIAN FOSSILS, 4TII CONTRIBUTION RESSER 25 



Stenothecoides troyensis, n. sp. 



Stenoihcca riigosa Walcott (part), U. S. Geol. Surv. Bull. 30, p. 128, pi. 12, 

 figs, id, e, 1886 (see HclcloncJIa riigosa) ; idem, loth Ann. Rep., p. 617, 

 pi. 74, figs, ih, i, 1891. 



This a very small species, and is much wider than any of the others. 

 Longitudinal curvature is accentuated at the anterior end so that a 

 slightly recurved apex is developed. 



Lower Cambrian, Schodack; (loc. 27) Troy, and other localities 

 in New York. 



Holotype.—-'U.S.'NM. no. 96484. 



Stenothecoides poulseni, n. sp. 



Undetermined lamellibranch Poulsen, Meddels Gr^nland., vol. 87, no. 6, p. 29, 

 pi. 7, figs. 1-4, 1932. 



It is possible that more than one species is represented by the speci- 

 mens illustrated. Growth lines are coarse and irregular. This species 

 is so constricted laterally toward the anterior end as to fortn a distinct 

 apex. 



Lower Cambrian, Ella Island ; south coast Ella Island, east 

 Greenland. 



Cotypes. — Min. Mus. Copenhagen. 



TUZOIA Walcott, 1912 



Tuzoia argenta (Walcott) 



Leperditiaf argenta Walcott, U. S. Geol. Surv. Bull. 30. p. 146, pi. 8, 

 fig. 5. 1886. 



jMiddle Cambrian, Ophir ; (loc. 30a) i tnile below Argenta, Big 

 Cottonwood Canyon, Wasatch Mountains; and (loc. 54a) Blacksmith 

 Fork, Bear River Range, Utah. 



Holotypc. — U.S.N.M. no. 15401. 



UNCERTAIN POSITION 

 UROTHECA Matthew, 1899 



Urotheca parasitum, n. sp. 



Hyolithclliis flagcUiiiii Walcott (part), Smithsonian Misc. Coll., vol. 67, 

 no. 2, p. 26, pi. 5, fig. 2a, 1917. 



This species consists of narrow, long flexible tubes which had one 

 or more longitudinal grooves. It is a much smaller tube than U. 

 Hagellum. The type and other specimens grew on shells of IVimanella, 

 which raises the question whether all species of Urotheca had such 

 s^rowth habit. 



