MACCOYA. 317 



This species is the type of Pomel's Wrightella, but its characters fit very well into the 

 genus Maccoya, and there seems no occasion for maintaining a separate genus for its reception. 

 Llandovery, Silurian (?), in conglomerate under the Worcester Beacon, England. 



*Maccoya sphaerica (M'Coy). 

 Plate 32, figs. 4, 5; Plate 34, figs. 4-10. 



Palaechinus sphacricus M'Coy, 1844, p. 172, Plate 24, figs. 5a-5c; Desor, 1858, p. 158; Dujardin and 

 Hupe, 1862, p. 464; Baily, 1865c, p. 89; Keeping, IS76, p. 38; Smith, 1901, p. 509; I*ml>ert and 

 Thiery, 1910, p. 119. 



Non Palaechinus sphacrirus Koninck, 1869, p. 546, Plate [not numbered], fig. 1; mm K'oninck, IS7(), p. 

 259, Plate 7, fig. 1; non Baily, 1874, p. 41; mm Zittel, 1879, p. 484; (pars) Lovn, 1874, p. 41; non 

 Neumayr, 1881, p. 151; non A. Agassiz, 1892, p. 73; (pars) Klein, 1904, p. 35. 1 



Palaeechinus sphaericut (pars) Lovdn, 1874, p. 41; Duncan, 1889, p. 196, text-figs, ii vii. 



Non Eriechinus sphacricus Pomel, 1883, p. 114. 1 



Non Typhlcchinus sphacricus Neumayr, 1889, p. 362, text-fig. 82c.' 



Non Palechinus sphacricus Tornquist, 1897, p. 736. 1 



Palaechinus sphericus (pars) Klem, 1904, pp. 34, 35. 



M'Coy's type of this species is in Dublin (Plate 32, fig. 5; Plate 34, fig. 7). In addition, 

 there are three specimens in the British Museum (Plate 32, fig. 4; Plate 34, figs. 4-6), three 

 in the Sedgwick Museum, Cambridge, England, and one in the Strassburg Museum (Plate 34, 

 figs. 8, 9), all of which are similar and are referred to sphaerica. 



M'Coy's type is almost spherical, but the height has to be estimated, as the dorsal part 

 is covered by a lump of the original matrix. Of this specimen the circumference at the mid- 

 zone measures 203 mm.; the diameter, in the same plane, 65 mm.; height, approximately 

 65 mm. ; width of ambulacrum B at the mid-zone, 6 mm. ; width of an interambulacrum about 

 34 mm. 



Ambulacra are narrow, rounded up in the center, so that the greatest elevation is in line 

 with the curvature of the interambulacra. Ambulacrum B is the only one in which the surface 

 of the plates is shown, other areas being internal molds for the most part. The details of 

 plate structure are difficult to ascertain, but Plate 34, fig. 7, was drawn at the point marked X 

 in Plate 32, fig. 5. As seen here, all ambulacral plates meet the middle of the area, but against 

 the interambulacrum alternate plates are primaries, marginally expanded, and intermediate 

 plates are narrowed and just cut off from contact with the interambulacrum. Pore-pairs 

 are biserial. In the British Museum and other specimens all ambulacral plates usually meet 

 the interambulacrum, though alternate plates are narrowed, and pore-pairs are biserial. 



1 These several references in the above paragraphs are all in regard to the specimen described by de Koninck as 

 Palaechinus sphaericus from Kirkby Stephen, Westmoreland, England. The specimen has a very different structure from 

 that of Maccoya sphaerica (M'Coy), and likewise different from that of the genera Palaeechinus and Maccoya. It is here 

 described as Lovenechinus lacazei (Julien), footnotes, pp. 303, 312, 326, also pp. 330-334, text-figs. 240-243; Plate 35, fig. 7. 



