304 THE CRINOIDEA CAMERATA OF NORTH AMERICA, 



Melocrinus sequalis S. A. Miller. 



1893. Adv. Sheets 18tli Rep. Geol. Surv. Indiana, p. 48, Plate 5, Eigs. 11 and 12. 



A moderately small species. Dorsal cup obpyramidal, decidedly pent- 

 angular at the arm bases, deeply sunken interradially. All plates of the 

 calyx heavy and tumid j those of the dorsal cup covered with short ridf>'es 

 at their margins, one to each side, the median portions of the plates 

 smooth. Suture lines well marked. The radial appendages directed almost 

 horizontally. 



Basals nearly equal, longer than wdde, the sides very little expanding. 

 Radials as long as the basals, a little wider than long. First costals hexa- 

 gonal, almost as large as the radials ; the second smaller and irregularly 

 axillary, giving off at the shorter side an armlet, and at the longer the next 

 order of brachials. Rays free above the costals, and evidently composed of 

 a single row of plates, with arms given off at alternate sides. Interradial 

 areas probably alike ; the first interbrachial nearly as large as the adjoining 

 costal, followed by two and three smaller plates, of which the latter occupy 

 the arm regions. Plates of the tegmen very large, composed of only two 

 rings, the upper supporting a massive anal tube, composed of tumid or nodose 

 plates. 



Horizon and Locality. — Niagara group, St. Paul, Ind. 



Bemarhs. — This species resembles M. parvus in having simple free rays, 

 but differs from it distinctly in the form of the calyx, the greater convexity 

 of the plates, in having a much stronger anal tube, and the rays directed 

 horizontally. 



Our description was made after Miller, and from fragmentary specimens in 

 our collection. 



11. DOLATOCRTNITES. 



> SYMMETRY OP THE DORSAL CUP UNDISTURBED BY ANAL PLATES. 



TECHNOCRINUS Hall. 



1859. Hall ; Palseont. New York, Vol. III., p. 139. 



1879. Ztttel; Handb. der PalEeont., Vol. I., p. 373. 



1881. W. and Sp. ; Revision Palseocr., Part II., p. 116 (Proceed. Acad. Nat. Sci. Phila., p. 290). 



1889, S A. Miller; N. Amer. Geol. and Palteont., p. 286. 



Calyx large; symmetry perfectly pentahedral up to the arm bases, 

 except a slight irregularity in the basal cup. Basals four, somewhat un- 



