I04 Bulletin 4 318 



CAL YPTRAPHORUS^ 



Calyptraphorus velattis var. compressa, PI. 10, figs. 7, a, b, 8. 



Syn. A7ichura White, U. S. Geol. Surv., Bull. No. 4, il 



p. 17. 

 Rosiellaria velata Aid., Geol. Surv. Ala., Bull. No. i, 



1886, p. 59. 

 Rostellaria Smith and Johnson, U. S. Geol. Surv., Bull. 



No. 43, 1887, p. 66. 

 Calyptraphorus velatus Harris, Geol. Surv. Ark., vol. ii, 



1892, p. 46. 

 Rostellaria (C.) velatus var. compressa Aid., Geol. Surv. 



Ala., 1894, p. 244, pi. 12, figs. 2, 2a, 2b. 



AldricJi' s characterization of this variety. — " This form is inter- 

 mediate between R. trinodifera Con. and R. velata Con. The adult 

 has the enamel on the front part as in R. trinodifera, but on the 

 opposite side the line of demarkation of the enamel comes down 

 only to the [body] whorl. The specimens are also much smaller 

 than the normal adult. A similar form that cannot be separated 

 from this variety is common in the Matthews' Landing group 

 but is nearly twice as large, more rotund than those figured. 

 The figures given are somewhat larger than the type." 



The smaller type of this variety is common in the lower and 

 medial Midway beds. It is one of the first to appear above the 

 Eocene-Cretaceous contact line. The larger specimens differ 

 from Calyptraphorus velatus from the Claiborne sand mainly by 

 the pointed exterior-posterior termination of the labrum; in 

 velatus this portion of the labrum is rounded, as shown by figure 

 5, plate 15, of Conrad's Fossil Shells, etc., 1835. 



Localities: — Texas : Brazos river, at and near the Cretaceous- 

 Eocene contact. 



Arkansas: Near Olsen's switch, a few miles S. W. 

 of Little Rock. 



Tennessee: Hannah's, i^ mi. N. or N. E. of 

 Crainesville; % mi. W. of Hannah's; Huddle- 

 ston's; Middleton. 



Mississippi: )^ mi. N. of Ripley; i mi. E. of Rip- 

 ley; y2 mi. S. of Ripley C. H. 



* Fischer in his Manuel de Conchy liologie, p, 672, has emended 

 the orthography of this word so that it reads Calyptrophorus . 

 Although we used the emended form of the word in the geologi- 

 cal part of this work, we do not hesitate, on further considera- 

 tion of the subject, to return to Conrad's original spelling. 



