38 BULLETIN 115, UNITED STATES NATIONAL MUSEUM. 



DOLATOCRINUS MULTIBRACHIATUS Rowley. 



Plate 9, figs. 3, 4. 



Dolatocrinus 7nultibrachiatus Rowley in Greene, 1903, p. 141, pi. 41, fig. 7. 



Founded on a specimen having' a calyx similar to that of D. spi- 

 nosus, but with an additional bifurcation in the rays, giving 40 arms. 

 I am able to confirm it by seven specimens of similar lorm having 

 one or more rays preserved, all of which have six or eight arms to the 

 ray. I have figured one of these, which is badly crushed, but shows 

 the surface characters better than the type, and another clearly show- 

 ing the numerous arms. 



Horizon and locality. — Onondaga (Jeffersonville) limestone: Louis- 

 ville, KentucW, and vicinity. 



HAMILTON SPECIES. 



[Valid species in italics; synon}Tns in romaii.] 

 With 10 arms. 



-Medium to large size. 



Calyx vride and low; ornament with sharp radiating striae. D. liratus. 



— var. miiltilira. 

 Calyx higher, ornament \ntli interrupted lines or pustules. D. glyptus. 



—var. intermedins. 

 Calyx, low, basin-shaped, with small l>asal pit; ornament 



variable, strong nodes or fine striae predominating D. asperaius. 



— marshi, var. hamiltoneneis. 

 Small, subglobose to oblate spheroidal. 



Strong central nodes, with coarse radiating striae; ridges 

 forming rim aroimd liasal pit. 



Calyx rather liigh D. bulbaceus. 



— pulchellus. 



— aspratilis. 



— subaculeatus. 



Calyx broader, ornament obscure D. argutus. 



With 10 to 20 arms. 



Small to medium size. 



Calyx decanter-shaped, truncate and broadly concave be- 

 low, basal caAdty bordered by prominent pentagonal rim. 

 Radial ridges and nodes inconspicuous; radiating striae 

 sharp, both fine and coarse. 

 Tegmeu liigh, conical, smooth; pinnule openings con- 

 spicuous. Tegmen not lobed. Arms about 15 D. stellifer. 



— hammelli. 



— iaguncula. 



— aplatus. 



— dissimilaris. 



— neglectus. 



Tegmen lobed. Arms 15 I), triadactvhis. 



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