NEVADA FOSSIL SPONGE FAUNA — BASSLER 99 



ing width representing the cloaca, emerging at the surface along the 

 upper thin edge in a row of narrow openings, each about 3 mm. long 

 and 1 nun. wide, spaced so that 4 or 5 occur in 20 mm. The usual 

 openings or oscula in the spicular tissue show on both sides of the 

 sponge, with an average of 4 pores in 3 mm. measuring longitudinally. 

 Cotypes.—V.S.^M. No. 79641. 



HESPEROCOELIA UNDULATA Bassler 



Plate 22, Figures .-?-5; Plate 24. Fiat ke 8 



This species differs from the preceding in forming undulated, often 

 convoluted bodies 8 cm. or more high and 1 cm, thick and in the fact 

 that the cloacal openings along the upper edge of the sponge are round, 

 3.5 to 4 mm. in diameter with 4 or 5 in 20 mm. Moreover, the small 

 pores penetrating the spicular tissue are more delicate and closely 

 spaced. 



Cofypes.—U.S.^M. No. 79642. 



Family ANTHASPIDELLIDAE Ulrich and Everett, 1890 



Sponges attached, saucer to funnel shaped, often turbinate with 

 canal system usually consisting of two sets, one radial and one vertical, 

 crossing each other at right angles. Skeleton of 4-rayed spicules con- 

 sisting of a rodlike central part and rapidly diverging bifurcations at 

 each end, uniting to form radial columns, which when connected by 

 the horizontal central rods form a minutely tubular meshwork. 



Genus ANTHASPIDELLA Ulrich and Everett 



Anthaspidella Ulrich and Everett, Geological Survey of Illinois, vol. 8, pp. 255, 

 256, 1890. 



Flat to saucer or funnel shaped sponges supported by a short sub- 

 cylindrical stem with the upper surface showing oscula, each provided 

 with its own system of radiating channels, all of which, however, merge 

 into the prevailing structure. Depressed part of each osculum occu- 

 pied by a few rather large, thin-walled, vertical tubes. Lower surface 

 of sponge occupied by rounded canal openings in spicular meshwork, 

 arranged in more or less radiating rows. 



Genotype. — Anthaspidella mammulata Ulrich and Everett. 



ANTHASPIDELLA CLINTONI Bassler 



Plate 23, Figure 9 



Sponge of large flattened disks, the type specimen a fragment 9 by 11 

 cm., indicating a diameter of at least 20 cm. for the entire body and 

 a maximum thickness of 1 cm. Although similar to Anthaspidella 



