100 PROCEEDINGS OF THE NATIONAL MUSEUM vol.91 



scutula Ulrich and Everett, from the Black River ( Platte ville) lime- 

 stone at Dixon, 111., in the small size and comparatively close arrang:e- 

 ment of tiie clnsters consisting of the oscula and radiating canals, the 

 present species differs in that the clusters measuring from center to 

 center are closer (15 nnn.) and coarser, and the canals are shorter, 

 broader, and less regularly arranged. 

 Holotype.—VS.'^M. No. 79643. 



ANTHASPIDELLA TRAINI Bassler 

 PLiVTE 2.3, FiGtJBES 7, 8 



Sponge suggesting Anthaspidella -florifera Ulrich and Everett, a 

 small saucer-shaped species from the Black River (Platteville) lime- 

 stone at Dixon, 111., but differing in that the body is flat, at least 20 cm. 

 in diameter, 1 cm. thick, and the clusters are coarser and farther apart, 

 ranging from 25 to 35 mm. distant from center to center. The canals 

 in each cluster are also fewer, broader, and radiately arranged. 



Holotype.—U.^.'^M. No. 79644. 



Genus STREPTOSOLEN Ulrich and Everett 



Streptosolen Ulbich and Evebett, in Miller, North American geology and 

 paleontology * * *, pp. 153, 165, 1889. 



The very irregular arrangement of the canals that pass through the 

 sponge mass in every direction is the chief character separating this 

 genus from AnthaspidelJa and other members of the family. Tlie 

 canals in Streptosolen intertwine to such a degree that it is difficult to 

 separate the two sets. 



Genotype. — Streptosolen ohconicus Ulrich and Everett. 



STREPTOSOLEN OCCIDENTALIS Bassler 



Plate 23, Figures 1, 2 



Sponge with the form and general structure of the genotype from 

 the Black River (Platteville) limestone at Dixon, 111., but differing in 

 that the canals do not intertwine so much and the centi-al osculum is 

 much wider and has larger tubes. 



Gotypes.—US.'^M. No. 79645. 



