ARCHAEOCIDARIS. 275 



*Archaeocidaris triserialis (M'Coy). 

 Plate 8, fig. 10; Plate 14, fig. 14 



Echinocrinus triserialis M'Coy, 1844, p. 173, Plate 26, fig. 1 (on the legend of Plate 26, fig. 1, the printed 

 generic name has been erased and Echinocrinus written in pencil; see footnotes, pp. 275, 277, 280). 



Archacocidaris triserialis Desor, 1858, p. 155; M'Coy, 1862 (on legend of Plate 26, fig. 1)^; Klem, 1904, 

 p. 58; Lambert and Tliiery, 1910, p. 125. 



Known only from primary .spines, which are triangular in section, each of the three angular 

 ridges armed with a row of strong tooth-like spinules; intervening space smooth; the sides 

 between the angles are flat and almost equal. Length of specimen that M'Coy figured is one 

 inch eight hnes, diameter one and a half lines; but it was incomplete at each end. . 



Arenaceous Limestone, Lower Carboniferous, Killycloghy, Lisbellow, County Tyrone, 

 Ireland. Holotype and only recorded specimen in the Science and Arts Museum, Dublin. Dr. 

 Scharff kindly sent me the photograph of this specimen which is here reproduced. 



*Archaeocidaris triserrata Meek. 



Plate 14, figs. 15a-15c. 



Archaeocidaris (?) triserrata Meek, 1872, p. 151, Plate 1, figs. 6a-6c. 



Archaeocidaris triserrata Miller, 1889, p. 225. 



Archaeocidaris triserata Keyes, 1895, p. 190. 



Archaeocidaris triserratm Klem, 1904, p. 58; Lambert and Thiery, 1910, p. 125. 



Known only from primary spines, which are moderately long, rather slender and usually 

 a little arched near the base, where they are nearly or quite circular in section. Farther up they 

 are compressed, rhombic in section, the lateral margins being sharp and regularly serrated, 

 the little tooth-like projections inchned outward, and toward the apex of the spine. There are 

 probably from 25 to 30 serrations on each side of the spine and from 9 to 12 of them may be 

 counted in the space of half an inch. On the middle of one face of the spine there is a third 

 serrated carina extending about two thirds the length of the spine ; on the other face three or 

 four rows of smaller granules or elongate nodes extend from the shank of the spine, but become 

 obsolete near the middle. Length about 2.30 inches. No entire specimens were found. 



Upper Coal Measures, near Omaha, Nebraska, cotypes in United States National Museum 

 Collection 6,599; Platte River, Nebraska; Vermilion County, Illinois; Kansas City, Missouri. 



'While Archaeocidaris triserialis is printed on the Plate as stated, Dr. Kitchin write.-! me that M'Coy (1862, p. 274) 

 in the list of errata says "Plate 26, fig. 1, read Echinocrinus instead of Archaeocidaris. (See footnotes pp. 277, 280.) 



