PLATE 38. 

 Lovenechinus lacazei (Julien). Page 326. 



Figs. 1-3. Lower Carboniferous, Hunsrucken, Prussia (after Tornquist, 1897, Plate 20, figs. 2-4). 



Fig. 1. Showing four columns of plates in an interambulacral area (p. 328). 



Fig. 2. Enlargement of ventral ambulacral plates of the same, plates are all primaries, pore-pairs in peripodia. 

 Fig. 3. Enlargement of ambulacral plates from the upper end of the corona, plates are occluded and demi-plates in each 

 half-area, pore-pairs biserial. 



Lovenechinus nobilis (Meek and Worthen). Page 335. 



Fig. 4. Same specimen as photograph, Plate 37, fig. 2. X 0.9. Ambulacral plates are demi- and occluded, five columns 

 of plates in an interambulacral area; tubercles are small secondaries only. The outline of ambulacrum J and the 

 outlines of plates in the lower part of interambulacra A and C are drawn from the mold of their internal faces. 



Fig. 5. Same specimen. X 2.7. Ambulacral detail and tubercles of plates from near the mid-zone as indicated by the 

 plate marked X in both figures. 



Fig. 6. Same specimen as photograph, Plate 37, fig. 3. X 3.5. Ambulacral detail of a half-area from near the mid-zone. 

 In four plates in this figure the inner tongue of the demi-plates is superficially separated from the outer portion of 

 tin' plates by the widening and confluence of the outer portion of the occluded plates. 



Fig. 7. Same specimen. X 3.5. Ambulacral detail from the same area near the apical disc. In the right half-area 

 there is one demi-plate, but other plates are all primaries and pore-pairs are uniserial. 



Fig. 8. Same specimen as photograph, Plate 37, fig. 1. X 0.9. Five columns of interambulacral plates in two areas. The 

 plates are very massive and thick. 



Fig. 9. Same specimen. X 0.9. Section, partially schematic, showing the curvature of the areas and ambulacral 

 plates beveling over the interambulacrals on the adradial sutures. Both ambulacral and interambulacral plates are 

 thicker in the middle of their areas than at the adradial sutures. The inner face of the test presents a curve of 

 one arc, thus differing from the exterior of the test where marked radial elevations occur in both ambulacral and 

 interambulacral areas. 



Lovenechinus mutatus (Keyes). Page 335. 



Figs. 10, 11 Keokuk Limestone, Lower Carboniferous, Keokuk, Iowa (after Keyes, 1894, Plate 15, figs. 4a, 4b). 



Holotype. 



Fig. 10. X 0.9. Five columns of plates in an interambulacral area. Ambulacral fields are strongly elevated in melon-like 



ribs. 

 Fig. 11. Same specimen, ambulacral detail enlarged. Plates occluded and demi-, a single row of tubercles only on a plate. 



The sutural contact of the demi- and occluded plates in each half-area is serrate, as in L. seplies (Plate 45, fig. 3) 



not deeply reentrant and tongue-like, as in L. nobilis, fig. 5. 



Figs. 1-3 copied by W. M. Barrows; figs. 4-9 drawn by J. Henry Blake; figs. 10, 11 from Keyes. 



