PLATE 40. 

 Lovenechinus missouriensis (Jackson). Page 337. 



Fig. 1. Same specimen as photographs, Plate 39, figs. 1, 2. X 2.5. A young specimen, the youngest of any known Palae- 

 ozoic echinoid, restored in part as indicated by dotted fines. There are fewer horizontal rows of interambulacral plates 

 than in the adult, only thirteen or fourteen plates in each of the adradial columns, therefore the point of origin of 

 column 5 is relatively much higher up than in an adult. In area E, column 5 is represented by only one plate, 

 and in area I, a sixth column is represented by a small plate dorsally. The oculars have each a pore and cover 

 the ambulacra and laterally the interambulacra in part on either side as usual (p. 341). For a view of the apical disc 

 of this specimen see Plate 41, fig. 2. 



Fig. 2. Same specimen. X 2.6. Drawn from a wax cast of a mold of the exterior, showing the ventral part of area E 

 with the introduction of columns 3 and 4, and tubercles; also ventrally, ambulacral plates, which at this zone are all 

 primaries. 



Fig. 3. Burlington Group, Lower Carboniferous, Webb City. Missouri. X 2.7. Mus. Comp. Zool. Coll., 3,078, holotype. 

 Ocular and genital plates enlarged. (Compare text-fig. 244, p. 338.) 



Figs. 1 and 2 drawn by J. Henry Blake; fig. 3 by J. H. Emerton. 



