178 SMITHSONIAN INSTITUTION 



Asaphocrinus incisus (Ringueberg) 

 Plate IV, fig. 30 



Lecanocrinus incisus Ringueberg, Bull. Buffalo Soc. Nat. Hist., V, 1886, p. 10, pi. 1, fig. 6. — Springer, 

 Jour. Geol. XIV, 1906, p. S°i. 



Similar to A. ornatus, but of more robust facies, and with calyx well 



differentiated by reason of the relatively much larger radials, smaller basals, 



and shorter primibrachs. Height of B to R to IBr is as 3:6:1.5. The calyx 



spreads less broadly, the height to width at top of radials being i to i.i; and 



the arms are heavier and shorter. Crown of type specimen is 19 mm. high; 



11 mm. wide at RR; base, 3 mm.; this specimen has but one primibrach in two 



of the visible rays, and in another specimen not figured the anterior radial is an 



axillary, supporting two rays about as large as the others. 



This form is rare, and may be only a sporadic variation in the large colony. 

 Types. In the author's collection. 



Horizon and locality. . Silurian, Niagaran, from the Homocrinus band in the upper part 

 of the lower third of the Rochester shales ; Lockport, New York. 



Asaphocrinus bassleri n. sp. 



Plate X, figs. 10-14 



Type of the genus. 



A large species, suggesting a cross between Pycnosaccus and Gnorimo- 

 crimis. Crown about as wide as high, obconical, broadly spreading from base to 

 the level of infolding about the fourth bifurcation. Calyx well differentiated, 

 turbinate or with slightly curved sides; height to width at top of RR, 1 to 1.8; 

 spread from base, 1 to 3.1. Anal tube long, with a strong dorsal series of plates 

 bordered by perisome. Surface smooth. In a mature specimen the crown is 

 28 mm. high by 26 mm. wide at the distal margin of infolded arms; calyx at top 

 of RR, 8 mm. high by 14 wide; base, 5 mm. 



IBB well developed, erect, forming a strong cone. BB much larger, slop- 

 ing rapidly outward ; post. B truncate, followed by large anal x, which is without 

 longitudinal curve or ridge. RR twice as large as BB, wider than high ; facet 

 for IBr considerably narrower than distal face, leaving strongly sloping should- 

 ers under the iBr areas, which are filled with an integument of plates larger than 

 usual in perisome, yet without definite arrangement. IBr short and wide, vary- 

 ing from 2 to 1 in the same specimen. Height of B to R to IBr, as 3.5 : 5 : 2.5. 

 IIBr usually 2, broad and often flat, and nearly as large as IBr. IIIBr and 

 IVBr variable in number, usually about half the size of those preceding, with 

 one nearly equal bifurcation beyond. Column cylindrical, much narrower than 

 the inf rabasal disk, not enlarging at the calyx ; composed of short, irregularly 

 alternating columnals for a considerable distance downward, beyond which they 

 become longer and uniform. 



