ANTHOZOA. 177 



COELENTERATA 



Class ANTHOZOA 

 Subclass Tetracoralla 



Family Zaphrentidae 



Genus Streptelasma Hall 



Streptelasma strictum Hall 



Plate 40, figures 5-11 



Streptelasma (Petraia) striata Hall, 1874, 26th Ann. Rept. N. Y. State Mus. Nat. Hist., 



p. 114. 

 Streptelasma stricta Hall, 1879, 32nd Ann. Rept. N. Y. State Mus. Nat. Hist., p. 142. 

 Streptelasma strictum Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. I, figs. 1-10. 

 Streptelasma strictum Hall, 1887, Pal. N. Y., vol. VI, p. 1, pi. I, figs. 1-10. 

 Streptelasma strictum Girty, 1895, 48th Ann. Rept. N. Y. State Mus. Nat. Hist., vol. II 



p. 300. 

 Enterolasma strictum Simpson, 1900, N. Y. State Mus., Bull. 39, p. 203, figs. 11, 12 



(p. 204). 

 Streptelasma strictum Weller, 1903, Pal. N. J., vol. Ill, p. 298, pi. XXXIII, figs. 3, 4. 

 Enterolasma (Streptelasma) strictum Shimer, 1905, N. Y. State Mus., Bull. 80, p. 235. 

 Streptelasma strictum Swartz, 1913, Md. Geol. Surv., L. Dev., p. 198, pi. XVII, figs. 5-9. 



Description — "Corallum simple, conicai, very gradually and regularly enlarging; 

 straight or very slightly curved, except at the apex, which is sometimes more abruptly 

 bent. Exterior marked with strong undulations of growth and numerous fine concentric 

 striae; external rays very prominent, from forty-five to fifty at a point where the diameter 

 of the corallum is 15 mm.; the increase in number taking place usually at three distinct 

 points, but sometimes at only two 



"Calix deep, sides thin and nearly erect; a flat space at the bottom In one calix, 

 having a diameter of 20 mm., there are fifty-four lamellae; alternate lamellae extending 

 only a short distance from the walls at the base of the calix and frequently coalescing 

 with the primary lamellae. For some distance below the calix-margin the lamellae are 

 of the same size, their edges smooth and rounded, becoming sharp below, and their sides 

 often distinctly granulose or spinulose. The primary lamellae unite and coalesce 

 at the center of the calix, forming an indistinct plate or vesiculose core from 3 to 5 mm. 

 in diameter. Fossette obscure or obsolete." — Hall, 1887. 



Dimensions — Figured specimens indicate range in size of coralla. 



Subclass Tabulata 



Family Favositidae 



Genus Favosites Lamarck 



Favosites helderbergiae Hall 



Plate 40, figures 12-17; plate 41, figure 1 . 



Favosites helderbergiae Hall, 1874, 26th Ann. Rept. N. Y. State Mus. Nat. Hist., p. 111. 

 Favosites helderbergiae Hall, 1879, 32nd Ann. Rept. N. Y. State Mus. Nat. Hist., p. 145." 

 Favosites helderbergiae Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. IV, figs. 1, 2; 



pi. V, figs. 1-3; pi. VI, figs. 1-8. 

 Favosites helderbergiae Hall, 1887, Pal. N. Y., vol. VI, p. 8, pi. IV, figs. 1, 2; pi. V, figs. 



1-3; pi. VI, figs. 1-8. 



