NO. 2247. SPONGES FROM NORTHWESTERN PA CIFW—HOZAWA. 545 



9. LEUCANDRA POCULIFORMIS, new species. 



Plate 84, fig. 4. 



Only a single specimen of this new species is represented in the 

 collection (Cat. No. 9189, U.S.N.M.). It has the form of a thick- 

 walled cup with a very irregular-shaped laterally compressed oscu- 

 lum at the upper end. The sponge was probably attached by the 

 inferior, somewhat narrowed, and broken-off end. It is nearly 38 

 mm. high and 28 mm. broad in the broadest part. The gastral 

 cavity is about 25 mm. deep The sponge wall is thickest in the 

 lower parts, where it measures 13 mm. in thickness. This dimin- 

 ishes gradually toward the sharp-edged oscular margin. To the 

 naked eye the outer surface appears nearly smooth. The gastral 

 surface is perforated by numerous small exhalant apertures of 2 mm. 

 and under in diameter. The color in alcohol is in part whitish and 

 in part more or less brownish. The texture is not very compact, but 

 rather soft and brittle. 



/Structure. — The canal system is leuconoid. The flagellate cham- 

 bers are ovoid or nearly spherical, measuring about 70-120[i. in their 

 longest diameter. They are thickly and irregularly set between the 

 branches of inhalant and exhalant canals, which are surrounded by 

 a fairly thick layer of mesogloea. 



The dermal skeleton is composed of several layers of variously 

 sized tangential triradiates. Microxea cover the external surface all 

 over, disposed at varying angles to it. The skeleton of the chamber 

 layer consists in the main of triradiates, which are of very variable 

 sizes and are thickly set together without any definite order. The 

 "wall of the larger exhalant canals is provided with a different sort 

 of triradiates besides having quadriradiates with apical ray project- 

 ing into the lumen. There exists a gastral skeleton which is fairly well 

 demarked from the chamber layer. It is composed of a thin layer 

 of tangential triradiates and of microxea, which occur moderately 

 densely together all over the gastral surface. The same kinds of 

 spicules as those of the larger exhalant canals are also found in the 

 gastral skeleton. Further, there occur in it some small and strongly 

 sagittal tri- as well as quadriradiated, both of which are, however, 

 not numerous. The oscular margin shows no special spicules. 



Spicules. — Dermal triradiates {a) regular or subregular. Rays 

 nearly equally thick, gradually tapering from base to sharp point, 

 very variable in si^e, 130-680[jl long and 20-60[x thick at base. 



Triradiates of chamber layer {b) regular or subregular, similar 

 to those of dermal skeleton, 280t640/i long and 40-60/x thick at base. 

 Much smaller triradiates occur in a small number. 



Triradiates of the larger exhalant canals {c) are sagittal. Eays 

 nearly equally thick, now lying all in one plane. Basal ray nearly 

 3343— 19— Proc.N.M.vol.54 36 



