THE MOUNT DESEET REGION 91 



thick stalk; usually they are irregularly leaf-shaped, Avith 

 the plane of the leaf curved so that the edges are in opposition 

 or overlapping. In one specimen the edges have almost com- 

 pletely coalesced so that the specimen is funnel-shaped. 



Skeleton. This is composed of a rather regular reticulation 

 of primary ascending fibers connected at intervals by trans- 

 verse secondary fibers. For the most part the fibers are 

 unispicular. 



Spicules. These are slightly curved oxea, varying in length 

 from .145 mm. to .186 mm., with the mode at .161 mm. The 

 size of the spicules is quite constant, although numerous 

 slightly shorter and much finer spicules which are immature 

 forms are present. 



Remarks. Lundbeck has described three new species: 

 Reniera parenchyma, folium, and hyalina, and there is no 

 reason to consider them more than varieties of Reniera 

 ventilabrum. 



R. parenchyma. '^ Erect, leaf-shaped, oblong-oval. The 

 dermal membrane thin, without spicules ; the ends of the fibers 

 projecting, and the surface consequently finely shaggy. Os- 

 cula small, only occurring on one side? The skeleton a regu- 

 lar network of primary and secondary fibers, the fibers 

 unispicular. Particular polyspicular fibers are found running 

 longitudinally through the sponge from the base. Spicula 

 curved, sharply pointed oxea, ca. 0.238 mm." (Lundbeck.) 



This species agrees as to the length of the spicules with 

 R. ventilabrum, but some of the spicules of R. parenchyma 

 are a ''little thinner in the middle than towards the ends." 

 This species was described from one incomplete specimen and 

 there is no assurance that this characteristic is constant and 

 nothing more than an individual variation, especially as not 

 all the spicules of this specimen exhibit this characteristic. 



R. folium. ''Erect, irregularly leaf -shaped, the leaves may 

 be irregular coalesced. The dermal membrane is thin without 

 spicules, and the ends of the fibers project, making the surface 

 finely shaggy. Oscula small, numerous, only found on one 

 side. The skeleton forms a regular network of primary and 

 secondary fibers, the fibers are unispicular. Particular poly- 



