238 CRUSTACEANS. 



and more flattened border ; segments ten, somewhat oblique, 

 well defined for three-fourths of the distance out, and thence 

 less distinctly so, to within a short distance of the margin ; a 

 few of the anterior ones with an obscure longitudinal furrow. 



Surface granular, the granules being largest on the poste- 

 rior portions of the glabella, palpebral lobes and neck segment. 

 On the segments of the axial lobe, both of the thorax and 

 pygidium, as well as those of the lateral lobes, they are very 

 small, and regularly disposed so as to form a single row on 

 each segment. (Meek.) 



Horizon and localities.— 1^0^ tTi Carboniferous, Keokuk 

 limestone : St. Francisville ( Clark county) ; Keokuk ( Iowa ). 



Phillipsia? immaturus (Herrick). 



Phoethonides immaturus Herrick, 1889: Bui. Dennison Univ., vol. IV. p 59, 

 pi. i, figs. 9 and 15. 



Closely related to P. tubereulata, but very much smaller. 

 Horizon and localities. — Lower Carboniferous, Lower Bur- 

 lington limestone : Louisiana. 



Phillipsia major Shumard 



Plate xxxij, figs. 8a- e. 



Phillipsia major Shumard, 1858 : Trans. St. Louis Acad. Sci., vol. I, p. 226. 

 Phillipsia 7najor Meek , 1872: U. S. Geol. Sur. Nebraska, p. 238, pi. iii, 



figs. 2a-c. 

 Phillipsia major Herrick, 1887: Bui. Dennison Univ. , vol. 11, p. 60. 

 Phillipsia major Vogdes, 18^*7 : Ann. N. Y. Acad. Sci., vol. IV", p. 85, pi. 



iii, fig. 14. 



Pygidium semi-elliptic, slightly longer than wide, broadest 

 anteriorly, very convex ; margins nearly straight on the sides, 

 rather sharply rounded behind. Median lobe considerably 

 raised above the lateral ones, distinctly compressed and fur- 

 rowed on each side, strongly arched longitudinally, and narrow- 

 ing posteriorly ; segments twenty-three in number, not curved 

 forward or backward, the ones toward the front not well defined 

 by sutural furrows. Lateral lobes broader than the central one, 

 turned abruptly downward on outer side, and sloping more grad- 

 ually behind into a smooth border which continues around the 

 free margins ; segments about thirteen, moderately oblique. 



