NO. lO CAMBRIAN FOSSILS, 4TH CONTRIBUTION RESSER 7 



Lingulella texana Walcott 



Obolus siiwe Walcott (part), U. S. Geol. Surv. Mon. 51, p. 415, pi. 26, 



figs. 2-2d, 1912. 

 Lingulella texana Walcott, Smithsonian Misc. Coll., vol. 53, no. 3, p. 71, 



pi. 8. fig. 5, 1908; U. S. Geol. Surv. Alon. 51, p. 535, pi. 49, figs. 3. 3a. 



Walcott's description stresses the radiating striae on the "outer 

 surface" of the shell as the diagnostic feature. When it is remem- 

 bered that the ribbing of a Lingulella shell is exposed only by exfolia- 

 tion of one or niore layers, this species loses its distinctive feature. 

 This explains why specimens which retained the outer shell layers 

 were referred to Obolus siiioc. 



Upper Cambrian, Wilberns ; (loc. 70) Baldy Mountain, 8 miles 

 northwest of Burnet, and (loc. 69) Honey Creek, 8 miles southeast 

 of Llano, Texas. 



Holotypc. — U.S.N.IM. no. 51806; paratype, no. 51805; plesiotypes, 

 no. 51627. 



Lingulella lochmanae, n. sp. 



Obolus (Lingulella) acutangulns Walcott (part), U. S. Geol. Surv. Mon. 



51, p. 474, pi. 17, figs. I, d, e, g, i, k, m-o, 1912. 

 Lingulella arguta Lochman, Journ. Pal., vol. 12, no. i, p. 85, pi. 18, figs. 



17-19, 1938. 

 Lingulella acutangula Bridge (part), in Sellards, Adkins, and Plummer, Univ. 

 Texas Bull. 3232, pi. 2, fig. 8, 1932. 



This is a medium-sized species which falls between such species 

 as L. alia. L. bunietensis and L. hridgci, on the one hand, and the 

 small species like L. texana, L. longula, and L. liilli on the other. 

 There is naturally variation in size. A large ventral valve is about 

 13 mm long and 8 mm wide. 



The specimens from locality 68 are doubtfully referred to the 

 species. In fact, it is not certain that all the others belong to one 

 species. 



Upper Cambrian, Cap [Mountain ; South Fork Morgan Creek, 4 

 miles northwest of Highway 29; Lion Mountain sandstone?; (loc. 

 68) near top of Packsaddle Mountain, 12 miles southeast of Llano; 

 Wilberns ; (loc. 69) Packsaddle ^fountain, and (loc. 69) Honey 

 Creek, 8 miles southeast of Llano, all in Texas. 



Holotype. — U.S.N.M. no. 95017; paratypes, nos. 27410, 27412, 

 51644. : 



Lingulella nina (Walcott) 



Obolus tctonensis ninus Walcott (part), U. S. Geol. Surv. Mon. 51, p. 418. 

 pi. II, figs, i-ig, 1912. 



