PLATE 39. 

 Lovenechinus missouriensis (Jackson). Page 337. 



Figs. 1, 2, 4-6. Burlington Group, Lower Carboniferous, Webb City, Missouri. Silicified internal molds with sutures 

 bounding the plates represented by elevated walls and pores by siliceous plugs or tubes. 



Fig. 1. Mus. Comp. Zool. Coll., 3,140 (from R. T. J. Coll.). Natural size. Young individual. Initial plate of column 5 

 in area A is at the mid-zone. The apical disc measures proportionately about 20 % of the diameter of the test. 

 Drawings, Plate 40, figs. 1,2; Plate 41, fig. 2 (p. 341). 



Fig. 2. Same specimen, enlarged. X 1.4. i 



Fig. 3. Burlington Group, Lower Carboniferous, Joplin, Missouri. F. Braun Coll. Natural size. Medium sized speci- 

 men. Five columns of plates in all interambulacral areas, oculars and genitals all in place, the latter with four or 

 five pores each. The apical disc measures proportionately about 21 % of the diameter of the test. Drawing, Plate 

 41, fig. 3 (p. 342). 



Fig. 4. Mus. Comp. Zool. Coll., 3,128 (from R. T. J. Coll.). Natural size. Old-age individual. Ventral view; ambula- 

 cra! plates ventrally are all primaries, higher up demi- and occluded; five columns of plates in interambul.-icral areas 

 A and C; a sixth column is represented by one or two plates in areas E, G, and I. Imperfect molds of jaws orally 

 (p. 342). 



Fig. 5. Same specimen, dorsal view. Natural size. Ambulacral plates at the mid-zone are demi- and occluded, but near 

 the apical disc all plates are primaries. vColumn 5 drops out dorsally in four interambulacral areas, also columns 1 

 and 2 in part are incomplete dorsally (compare Plate 42, fig. 6). The apical disc is small measuring proportionately 

 about 16 % of the diameter of the test. Oculars are all in place and against them the youngest interambulacral 

 plates are in contact. Genitals are all in place, each with three or four pores, which are represented by tubular sili- 

 ceous casts of the original pores. There are impressions of a few periproctal plates. The bounding margins of each 

 plate are represented by thin siliceous walls as seen best in interambulacra E and G (p. 22). Drawings of iisis. 

 4 and 5: Plate 41, fig. 1; Plate 42, figs. 6, 7 (p. 342). 



Fig. 6. Mus. Comp. Zool. Coll., 3,131 (from R. T. J. Coll.). Natural size. Shows ambulacral plates, all primaries ven- 

 trally; higher up, occluded and demi-plates. Plates opposite the horizontal sutures of adnidial plates arc fan- 

 shaped in this internal view. Drawing, Plate 42, fig. 5 (p. 346). 



