98 PROCEEDINGS OF THE NATIONAL MUSEUM vol.91 



tissue, these in the present case being about 0.35 mm. wide and separated 

 by their own diameter. 



Cotypes.—U.S.^M. No. 79639. 



PATELLISPONGIA MINUTIPORA Bassler 



Plate 21, FiGimEs 1, 2 



Sponge consisting of a thhi, expanded, smooth lamella, 12 em. or 

 more wide and 4 mm. thick, differing particularly from other members 

 of the genus in the minuteness and close spacing of the pores on both 

 sides. At least 15 pores can be counted in 10 mm. on the upper surface, 

 where they occur at regular intervals and average 0.5 mm. in width. 

 The basal surface shows pores of about the same dimensions as the 

 upper but arranged in longitudinal parallel series. 



Eolott/pe.—U.S.^M. No. 79640. 



PATELLISPONGIA MAGNIPORA, new species 



Plate 21, Figure 6 



Sponge a unilamellar expansion 10 cm. or more broad, 3 to 8 mm. 

 thick, with a smooth but minutely porous base and an upper surface 

 marked by wide, open canals 2 to 2.5 mm. in diameter, irregularly 

 arranged and spaced at distances several times their width in the usual 

 spicular tissue. The minute pores of the basal side are closely spaced 

 in equally closely arranged parallel longitudinal rows with 7 pores in 

 5 mm. measured longitudinally, each pore about 0.6 mm. wide. 



The surface pores or canal openings in the species, represented by 

 four specimens, are the largest so far noted in the genus, which fact in 

 addition to their irregular arrangement causes easy recognition. 



Holotype.—U.S.'NM. No. 99602. 



Genus HESPEROCOELIA Bassler 



General structure as in PateUisp07igia except that the broad, thin, 

 saucer-shaped lamella of that genus is here represented by a flat, undu- 

 lated frond or convoluted sponge body with pore openings of similar 

 size and arrangement on each face but penetrated lengthwise by a cloaca 

 in the form of a narrow to broad, flattened tube or series of tubes, open- 

 ing along the upper edge in a row of rounded or oval apertures. 



Genotype. — Hesperocoelia typicalis Bassler. 



HESPEROCOELIA TYPICALIS Bassler 



Plate 22, Figures &-8 ; Plate 24, Figure 9 



Sponge a smooth, flattened, flabellate frond, 5 cm. or more in diameter 

 and about 6 mm. in thickness, traversed by longitudinal canals of vary- 



