832 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 



symmetry of the Crinoids generally. , Another most remarkable feature, 

 which separates this family distinctly from all other Camerata, is the com- 

 partments enclosing the arms, which are formed by processes or partitions 

 attached to the outer sides of the disk, and are supported by the inter- 

 brachials and interdistichals. 



The family was restricted to the Upper Silurian, with the exception of 

 a single species found in the lower Devonian of the Eifel. It was the lead- 

 ing family of its epoch in the number of species discovered, there being 

 twenty-one from America, and eighteen from England and Sweden, but only 

 two genera. 



EUCALYPTOCRINUS Goldf. 



1826. GoLDPUss; Petref. German., Vol. I., p. 214, and 1838, Nova Acta Leop. Yol. XIX., 1, p. 335. 



1841. MtJLLER ; Bed. Akad. d. Wissensch., p. 210. 



1841. Hall ; Paleeont. N. York, Vol. I.I., p. 207. 



1843. RoEMEn; Rhein. Uebergangsgeb., p. 62, and 1855, Lethaea Geogn. (Ausg. 3), p. 257, and 1860, 



Siliir. Fauna West. Temi., p. 48. 

 1853. De Koninck and Leiion ; Recher. sur les Crinoides du Terr. Carbonifere de la Belgique, p. 74, with 



diagram. 

 1857. PiCTET; Traite de Paleontologie, Yol. lY., p. 307. 



1862. DujARDiN and Hupe; Hist. Nat. des Zoopli. Echin., p. 115. 



1863. Hall; Trans. Albany Inst., Yol. lY., p. 197. 

 1866. Schultze; Monogr. Echin. Eifl. Kalk., p. 90. 



1878. Angelin; Iconogr. Grin. Suec, p. 16. 



1879. Hall; 28th Rep. New York State Mus. Nat. Hist., (Ed. II.), p. 141. 

 1879. Zittel; Ilandb. der Paleeontologie, Yol. L, p. 379. 



1885. Quenstedt; Handb. d. Petrefactenkuude (Ausg. 3), p. 963. 



1885. W. and Sp. ; Revision Palseocr., Part III., p. 127 (Proceed. Acad. Nat. Sci. Phila., p. 349). 



1889. S. A. MiLLEU; N. Amer. Geol. and Palfeont., p. 243. 



Syn. Hi/panfhocrinus Phillips, 1839; Murchison's Silur. System, p. 672, Plate 17, Eig. 3; Zittel, 

 1879 ; Angelin, 1878 ; S. A. Miller, 1880. 



Calyx with the arms attached more or less ovate ; without the arms 

 resembling a wine bottle with concave bottom and slender neck ; the neck 

 surrounded by ten longitudinal partitions closed from above, and forming 

 ten niches or compartments into which the arms, in pairs, and to their full 

 length, exactly fit. Dorsal cup composed of four basals, five radials, 2x5 

 costals, 2X10 distichals, 1 X 20 palmars, 3x5 interbrachials, and 1x5 inter- 

 distichals. The basals, which form an inverted funnel-shaped cup, are not 

 visible from a side view, and the calyx rests upon the edges of the inflected 

 lower portions of the radials ; the plates varying in size, the anterior one 

 larger than the rest. Axial canal five-rayed, the anterior basal pierced by 

 two of its rays. First costals quadrangular, the second pentangular unless 

 the upper angle is truncated by the interdistichal. First distichals larger 



