BEL. CAC.] 



ECHINODERMATA. 



229 



BELEMNOCRINUS, White, 1862, Proc. Bost. Soc. 

 Nat.Hist., vol. 9, p. 14. 

 [Ety. belemnon, dart, 

 javelin ; krinon, lily.] 

 Basals 5, large, long, 

 narro w and of irregular 

 shape; radials 5; arms 

 10, with one or two 

 syzygies in each joint; 

 pinnules long, arm- 

 like, and bifurcating; 

 azygous plate rests be- 

 tween radials, and 

 upon one of the basals, 

 and supports a large 

 ventral sac composed 

 of numerous hexago- 

 nal plates ; column 

 pentagonal, with or 

 without lateral cirrhi. 

 Type B. typus. 



florifer, Wachsmuth & 

 Springer, 1877, Am. 

 Jour. Sci. and Arts, 

 3d ser., vol. 13, p. 256, 

 Burlington Gr. 



pourtalesi, Wachsmuth 

 & Springer, 1877, Am. 

 Jour. Sci. and Arts, 

 3d ser., vol. 13, p. 258, 

 Burlington Gr. 



typus, White, 1862, 

 Proc. Bost. Soc. Nat. 

 FIG. 255.-Belem- Hi t vol 9 p- 14 

 nocrmus typus. BurlingtO n Gr. 



whitii, Meek & Worthen, 1866, Proc. Acad. 

 Nat. Sci. Phil., p. 251, and Geo. Sur. 

 111., vol. 3, p. 463, Burlington Gr. 



cavity ; the deltoids occupy the whole 

 space between the pseudambulacra ; 

 the orifices unknown; column round. 

 Type B. carcharidens. 

 carcharidens, Bill- 

 ings, 1859, Geo. 

 Sur. of Can., Dec- 

 ade 4, p. 18, Chazy 

 Gr. 



BBACHIOCRINUS, Hall, 

 1859, Pal. N. Y., 

 vol. 3, p. 118. [Ety. 

 brachium, an arm ; 

 krinon, lily.] 



Founded u p"o n FIG. 257. Blastoldocri- 

 arms rounded at n^chariden,^ 

 the base, com- tending the whole 

 posed of single ar- length of the pseud- 

 ticulating plates ambulacra, 

 having thickened, node-like joints, and 

 bearing pinnules. Type B. nodosarius. 

 nodosarius, Hall, 1859, Pal. N. Y., vol. 3, 

 p. 118, Low. Held. Gr. 



BURSACRINUS, Meek & Worthen, 1861, Proc. 

 Acad. Nat. Sci. Phil., p. 136. [Ety. 

 bursa, purse ; krinon, lily.] Calyx some- 

 what like Graphiocrinus, but arms 

 widely different ; basals 5 ; subradials 

 5 ; radials 2x5; regular interradials ; 

 azygous interradial 1 ; arms wide, flat, 

 jointing below, in compact series, and 

 bifurcating above. Type B. wach- 

 smuthi. 



confirmatus, White, 1862, Proc. Bost. Soc. 



Nat. Hist., vol. 9, p. 11, Burlington Gr. 



wachsmuthi, Meek & Worthen, 1861, Proc. 



Acad. Nat. Sci. Phil., p. 137, and Geo. 



Sur. 111., vol. 3, p. 479, Burlington Gr. 



Fro. 2.56. Beleraiiocrinus whitii. 

 Diagram x 2. 



BLA.STOIDOCRINUS, Billings, 1859, Can. 

 Org. : Rem., Decade 4, p. 18. [Ety. 

 blastos, a bud ; eidos, form ; krinon, 

 lily.] The general form is like a 

 Pentremites ; basals do not rest 



FIG. 258. Bursacrinus wachsmuthi. Diagram. 



upon the top of the column, but have 

 their inner edges turned upward, and 

 the^column passes on into the visceral 



Cacabocrinus, Troost, 1850. Never de- 

 scribed. The fossils referred to it be- 

 long to Dolatocrinus. 



