ICHTHY0CR1NIDAE 283 



new and accurate drawings of the original specimen in several views (PL XXXIV, figs. 

 iia-f). This specimen is peculiar in having an extra primibrach in the left anterior as well 

 as the right posterior ray — the only case of the kind I have seen in Ichthyocrinus. There are 

 also figured two other fragments showing the base (figs. 12, 13), both in the Riks Museum at 

 Stockholm. In general proportions these specimens closely agree with those from America, 

 and the radial ridges are similarly conspicuous. I have a single specimen from the approxi- 

 mately equivalent Wenlock formation at Dudley, England (fig. 14), which I have referred to 

 the same species, though it is perhaps not a very characteristic form ; it has about the same 

 proportions, rather obscure radial ridges, and a perfectly smooth surface ; but the basals are 

 not quite so well developed as in the Swedish specimens ; and it does not agree with any 

 other species, differing wholly in the surface from /. pyriformis under which name it was 

 labeled. 



Types. The Swedish specimens are in the Riks Museum, Stockholm ; that of figure 14 

 is in the author's collection. 



Horizon and locality. Silurian, Wenlock Group ; Gotland, and England. 



Ichthyocrinus conoideus Ringueberg" 

 Plate XXXVI, figs. 8-12 



Ichthyocrinus conoideus Ringueberg, Annals New York Acad. Sci., V, 1890, p. 305, pi. 3, fig. 5. 



A rather small species. Crown narrow, elongate conical, with straight 

 sides to level of IIBr 3 where height to width is 1. 1 to I, expanding very greatly 

 above that; spread of calyx from RR to IAx, about i to 1.2; to IIBr 3 , about 1 

 to 3 ; base truncate ; cross-section circular. Surface smooth, without radial 

 angularity, and plates not imbricated in lower part. Largest specimen, 22 mm. 

 high by 20 mm. wide at top of IIBr 3 . 



IBB small. Basals small, exposed only as triangles in side view. Brachials 

 without longitudinal elevation. IIBr 4. Superior parts and column unknown. 



This species occurs at Lockport, New York, in the Gasport limestone, a horizon above 

 that of /. laevis. Ringueberg's original material was imperfect, he having but three frag- 

 mentary specimens in all, and only one of these has the plates preserved as high as IIBr 3 . 

 I have recently obtained about a dozen additional specimens from the same beds, none of 

 them perfect, but some preserving the plates to the fourth IIIBr ; they show the extreme 

 narrowness of the lower calyx as seen in Plate XXXVI, figures 9 and 12a, a character 

 not so evident in Ringueberg's figured type (fig. 8a) as in the other specimens used by him; 

 figure 11 shows the contour of the crown to what is probably the widest zone. Most of the 

 specimens have the base very well preserved, and they agree perfectly in the small size of 

 the basals, thus, distinguishing the species at once from /. subangularis which it nearest 

 resembles in figure. The brachials throughout are relatively very high, indicating an 

 extremely elongate crown; yet specimens with the highest brachials (e. g., figs. 12a, b) have 

 the small basals almost covered by the column, and visible only as small triangles in a side 

 view. They all lack the strong radial ridges and general angularity of /. subangularis, the 

 strongly curving side outline of I. laevis, and the well-developed basals of both these species. 



Type. This and the other specimens figured are in the author's collection. 



Horizon and locality. Silurian, Gasport limestone of the Niagaran ; Lockport, New 

 York. 



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