ICHTHYOCRINIDAE 275 



Types. According to Murchison (Silurian System, p. 702) Phillips's figure and descrip- 

 tion were made from a specimen belonging to Mrs. Downing of Dudley, England, but its 

 present whereabouts is unknown. Of the others figured on Plate XXXII, figures 4, 5, 6, 8 

 are in the British Museum ; 9, 10, II, 12 and 13 in the Riks Museum, Stockholm; and 2, 3, 7 

 in the author's collection. 



Horizon and locality. Silurian, Wenlock Group. Chiefly at or near Dudley, England ; 

 Wisby, Dalham, Faro, and Follingbo (horizon /), Island of Gotland. 



Ichthyocrinus gotlandicus Wachsmuth and Springer 

 Plate XXXV, figs. 1-16 



Ichthyocrinus gotlandicus Wachsmuth and Springer, Revision Palaeocrinoidea, pt. I, 1879, p. 34. — 



Springer, Jour. Geology, XIV, 1906, pi. 6, fig. 6. 

 Ichthyocrinus laevis, Angelin (in part), Icon. Crin. Sueciae, 1878, p. 13, pi. 22, figs. 20, 21, not pi. 9, 

 figs. 17, iya-c. 



A small species. Crown ovoid to low pyriform, with truncate base; ex- 

 panding rapidly from base beyond IIBr, the spread of calyx from RR to upper 

 IIBr being i to 4; height to width at same level, about 1 to 1.6. Side outline of 

 calyx curving from concave to convex; no radial ridges; cross-section circular. 

 Surface ornamented with small raised pustules. Plates but little imbricated. 

 Maximum crown, about 25 mm. high by 17 mm. wide at upper IIIBr; a larger 

 fragment, 13 by 20 mm. at upper IIBr; average width of base, about 4.5 mm. 



IBB very small, usually atrophied or entirely wanting. BB small, re- 

 stricted to the column facet, or visible in side view only as mere points. RR and 

 RA touching the column, RA usually entirely covered by it. IIBr generally 3 ; 

 IIIBr 4 to 7. Average height to width of brachials above IBr, about 1 to 3. 

 Column unknown below proximal columnals, which are as wide as the base. 



In his Iconographia Crinoideorum Sueciae, Angelin figured two specimens from 

 Gotland which he referred to Ichthyocrinus laevis of Conrad and Hall {op. cit., pi. 9, 

 figs, lya-c; pi. 22, figs. 20, 21). Wachsmuth and Springer x disagreed with this identification, 

 holding the Swedish specimens to be distinct from the New York species ; and proposed for 

 them the name /. gotlandicus upon the grounds stated. A careful examination of Angelin's 

 specimens, together with several others since discovered, confirms their separation from the 

 American form ; but it also raises a rather close question as to what should be called /. got- 

 landicus, owing to the fact that the two specimens figured by Angelin and included in 

 Wachsmuth and Springer's reference do not themselves belong to the same species. Our 

 diagnosis of the species must b'e gathered from the following paragraph in the Revision, 

 P-34: 



The European form is pear-shaped instead of ovoid, the plates ornamented, but without any surface 

 angularity, and with nearly straight sutures ; while the New York specimens have plates with smooth but 

 angular surface, and very distinct waving sutures. 



As to the general form we were misled by the figures of Conrad and Hall, which as 

 elsewhere explained appear ovoid merely because made from flattened specimens, whereas 

 I. laevis in its undistorted condition is pyriform. Furthermore, only one of Angelin's speci- 

 mens (Icon. Crin. Suec, pi. 9, fig. 17) is pyriform, the other being a low ovoid (see my 

 Pi. XXXV, figs. \a, b). The distinction based upon the sutures must also be abandoned, 



'Revision of the Palaeocrinoidea, pt. I, 1879, p. 34. 



