Contributions to Invertebrate Palaeontology. 5TT 



Cyatliocriniis Maxvilleiisis, n. sp. 



Plate XIII, figs. 5-8. 



Cyatliocriniis ineqaidactylus Wliitf., Ann. N. Y. Acad. Sci., 1882, p. 219. 

 Not C. inequidadylus (McCoy) W. and Sp. 



Body of rather small size. Calyx deep cyathiform, being nearly hemi- 

 spherical in one example, and somewhat broad obconical in another, and 

 composed of smooth plates, which have only the general convexity of the 

 body, or very slightly tuberose. Basal plates minute to moderate size, higher 

 than wide. Subradials large ; lieight and width nearly equal ; two of them 

 heptagonal and the others hexagonal, the lower sides barely diverging from a 

 straight line. First radials wider than high, and about two-thirds as high as 

 the subradials. Anals visible, three in number ; the first elongate pentagonal, 

 nearly twice as high as wide, and situated a little obliquely on the right side 

 of the area; the other two are small and pentagonal. Second radials, or first 

 arm-plates, smaller than the first radials and narrowing upward, wedge-formed 

 above, and each supporting two arms. On the postero-lateral rays they are 

 long and cylindrical, with the arms slender. On the anterior ray it is short 

 and supports two slender arms ; while on the antero-lateral rays they support 

 a slender arm similar to those of the other rays on the anterior side, and on 

 the outer side an arm several times larger and stronger than the others, and 

 composed of larger and stronger plates. 



Plates of the arms short and unequal-sided, and giving origin to jointed 

 tentaculse from the longer side of each plate, which is upon the alternate 

 sides of the arm, or on the same side from every second plate. Surface of the 

 plates smooth. Length of the arms and subsequent bifurcations not known. 

 Column small, round, and composed of unequal-sized plates alternating with 

 each other. 



The slender arms are preserved on two individuals to the length of about 

 one inch, and the strong antero-lateral arm on one, to more than an inch ; 

 but no evidence of bifurcation appears. 



The inequality of the antero-lateral arms will be the distinctive 

 feature of the species, as the form of the calyx is similar to many 

 other species of the group. 



Formation and Locality. — In the Maxville limestone (shaly por- 

 tion), at Newtonville, Ohio. 



BLASTOIDEA. 

 Genus PERfTREMITES Say. 



Pentreiuites elegans. 



Plate XIII, fig. 4. 



Pentremites elegans Lyon, Trans. Acad. Sci. St. Louis, vol. 1, p. 632, pl. 20, fig. 4. 



Body small, broadly subpyriform, the length equal to about once and a half 

 the height, but somewhat variable with age ; the greatest width being at the 



