PLATE 47. 

 Maccoya gigas (M'Coy). Page 321. 



Fig. 1. Lower Carboniferous, Rahan's Bay, Ireland. Sedgwick Museum Coll., Cambridge, England, 3 (drawn from the 



original specimen of Keeping's, 1870, Plate 3, fig. 13). X 4.7. Ambulacral plates are alternately primaries and 



occluded, pore-pairs biserial. 

 Fig. 2. After Baily, 1877, Plate 3, fig. C. Same specimen as photograph, Plate 46, fig. 1. Cotype. X 1.6. All ambulacral 



plates reach the middle of the area, but alternate plates are primaries, meeting the interambulacrum, or occluded 



plates, which are cut off from interambulacral contact; pore-pairs biserial. 



Lovenechinus anglicus sp. nov. Page 346. 



Fig. 3. Same specimen as Plate 46, fig. 5. Holotype. X 0.9. This specimen, well preserved in many points, presents 

 a curious case showing how parts may be shifted about. Interambulacrum A and the right half of ambulacrum B 

 are quite complete; the left half of ambulacrum B and a large part of interambulacrum C are pushed to the right 

 under the adjacent areas. In interambulacrum A there were at least six columns of plates; column 2 is assumed 

 as indicated by dotted lines. In ambulacrum B ventrally the plates arc primary and occluded, seen also ventrally 

 in area D; higher up the plates are all demi- and occluded. This specimen is apparently the original of that which 

 was described and figured by Duncan, 1889, p. 198, text-fig. I, as Palaeechinus gigas. Further, it is the original which 

 I described and figured as Palaeechinus gigas (see Jackson, 1896, p. 204, Plate 7, figs. 38, 39). 



Fig. 4. Same specimen. Ambulacral plates from the ventral region. X 3.5. All plates meet the middle of the area, but 

 alternate plates are primaries, meeting the interambulacrum and occluded, which are cut off from interambulacral 

 contact. Compare Plate 42, fig. 1. 



Fig. 5. Same specimen, ambulacral plates from near the mid-zone. X 3.6. The occluded plates alone meet the middle 

 of the area, demi-plates are narrower, laterally meeting the interambulacrum, and on their inner border fit between 

 the outer ends of the occluded plates in a tongue-like fashion. 



Oligoporus blairi Miller and Gurley. Page 351 



Fig. 6. Same specimen as photograph, Plate 48, fig. 1. X 2.3. The holotype of Oligoporus bellulus Miller and Gurley, 

 here considered a synonym of blairi. Ambulacrum with four columns of plates, demi- and occluded, also scattered 

 isolated plates near the middle line of the half-areas. In area A there are four columns of interambulacral plates, 

 a case of extreme arrested radial variation; in another area, C, of this specimen, which is only preserved dorsally, 

 there are seven columns of interambulacral plates. Tubercles and spines are shown on one interambulacral plate 



Fig. 7. Same specimen as photograph, Plate 49, fig. 1. Cotype of O. blairi. X 2.4. Section just above the mid-zone, 

 ambulacrum with occluded, demi-, and scattered isolated plates, seven columns of plates in interambulacrum A. 



Oligoporus coreyi Meek and Worthen. Page 353. 



Fig. 8. Same specimen as photograph, Plate 48, fig. 2. Holotype. X 2.4. Section of an interambulacrum at the mid-zone 

 showing six columns and the initial plate of a seventh column with its adjacent heptagon. 



Fig. 9. Same specimen and areas at the mid-dorsal portion. X 2.3. Interambulacral columns have dropped out to five, 

 ambulacrum with wide occluded, proportionately rather wide demi-, and scattered isolated plates. 



Oligoporus sulcatus Miller and Gurley. Page 354. 



Fig. 10. Same specimen as photograph, Plate 48, figs. 3, 4. Holotype. X 2.3. Section near the mid-zone, ambulacrum 

 with occluded, demi-, and scattered isolated plates, seven columns of interambulacral plates in area I; the initial 

 pentagon of column 7 with its adjacent heptagon appears in this view. Only the left half of ambulacrum H is shown, 

 and as the sutures of plates are obscure they are in part shown by dotted lines. 



Oligoporus halli sp. nov. Page 355. 



Fig. 11. Same specimen as photograph, Plate 48, fig. 5. Holotype. X 0.9. The ambulacrum near the mid-zone with 

 occluded, demi-, and scattered isolated plates; eight columns of plates in interambulacral area C. In interambula- 

 crum A the first two rows are restored as indicated by dotted lines. Column 3 originates in the second row, column 4 

 in the third row, and column 7 to the left of the center. In area C column 8 originates at about the mid-zone. 



Fig. 12. Same specimen; enlargement of ambulacral detail. X 2.3. 



Oligoporus danae (Meek and Worthen). Page 356. 



Fig. 13. Keokuk Group, Lower Carboniferous, Jersey County, Illinois. F. Springer Coll. 8,124. X 2.3. Plates with 

 s] lines in place. 



Figs. 1, 2, 6-13 drawn by J. Henry Blake; figs. 3-5 by G. C. Chubb. 



