16 BULLETIN 64, UNITED STATES NATIONAL MUSEUM. 



Observations. — This species is separated from P. godoni by Hambach 

 on account of the more elongate base (see p. 13), and from P. pyri- 

 formis in having the greatest diameter below the center as noted in 

 connection with the latter species (see p. 14). 



The variety elongatus is separated only on account of its more elon- 

 gate form, but the individuals of the species show so much variation 

 in proportional length that it seems inadvisable to establish a variety 

 on this feature alone, in the absence of a figure or more detailed 

 description. 



The Pentremites godoni var. jlorealis of Etheridge and Carpenter 

 [1886, p. 160] is separated from P. godoni as a variety "in which the 

 bodies of the radials are very much inclined to the vertical axis of 

 the calyx." It is thus quite different from P. Jlorealis as defined by 

 Hambach, and, as shown by the ngure, a is closely allied to P. godoni. 



Cat. No. 33070, U.S.N.M. 



PENTREMITES SULCATUS Roemer, 



Plate 3, figs. 14, 15, 16. 



Pentremites cheroheus Troost, Proc. Amer. Ass. Adv. Sci., II (read 1849), 1850, 

 p. 60 (nomen nudum); MSS., 1850.— Hall, Rep. Geol. Surv. Iowa, I, Pt. 2, 

 1858, p. 691, pi. xxv, figs. 12a, 6.— Weller, Bull. No. 153, U. S. Geol. Surv., 



1898, p. 412 (catalogue name). 



Pentremites laterniformis Owen and Shumard, Journ. Acad. Nat. Sci. Phila. 



(2), II, 1850, p. 66, pi. vii, fig. 15. 

 Pentatrematites sulcatus Roemer, Archiv. fur Naturg., Jahrg. XVII, 1, 1851, p. 354, 



pi. vi, figs. 10a, c. 



Pentremites sulcatus Shumard, Marcy's Expl. Red Riv. Louisiana, 1854, p. 174; 

 Trans. Acad. Sci. St. Louis, I, No. 2, 1858, pp. 243, 246; II, 1866, p. 385 (cata- 

 logue name). — Lyon and Casseday, Proc. Amer. Acad. Sci., IV, 1860, p. 

 298. — Bronn, Klassen und Ordn. Their-Reichs., II, 1860, pi. xxm, figs. 

 lf-j. — Dujardin and Hupe, Hist. Nat. Zooph. Ech., 1862, p. 91. — Eth- 

 eridge and Carpenter, Cat. Blastoidea, 1886, p. 165, pi. i, figs. 8-10; pi. n, 

 fig. 31; pi. xvi, fig. 20; pi. xvm, fig. 5. — Keyes, Missouri Geol. Surv., IV, 

 1894, pi. xvm, figs. 6a, b.— Weller, Bull. No. 153, IT. S. Geol. Surv., 1898^ 

 p. 416 (catalogue name). — Bather, List Blastoidea Brit. Mus. (Nat. Hist.), 



1899, p. 54 (catalogue name). — Hambach, Trans. Acad. Sci. St. Louis, XIII, 

 1903, p. 39, pi. vi, figs. 1-12. 



Pentatrematites sulcatus Roemer, Bronn's Lethaea Geognostica, 3rd ed., Pt. 2, 



1852-54, p. 282, pi. iv, figs. 9a, b. 

 Pentremites robustus Lyon, Trans. Acad. Sci. St. Louis, I, 1860, p. 629. 



The following is the original description by Troost : 



Transversely pentagonal, longitudinally pyramidal, the plates inclosing the ambu- 

 lacra longitudinally deeply excavated and bent outwardly near the summit. Ambu- 

 lacra long, reaching the pelvic plates — Pelvis very short. 



On the base of the Look-out Mountain, Cherokee County, Tennessee. 



Observations. — This species was described by Hall under the name 

 of Pentremites cherokeeus, with P. sulcatus Roemer cited as a synonym. 



a Etheridge and Carpenter Catalogue of the Blastoidea, pi. 2, fig. 3. 



