1887.] NATURAL SCIENCES OF PHILADELPHIA. 247 



in size, that is, in the slenderness of their fronds ; but in the one case 

 these terminated abruptly in sharp points, — in the other they were 

 rounded as above described, and reminded me of the bi'oadly pal- 

 mate antlers of a stag. On reaching my microscope their generic 

 difference was quickly discovered. 



The name I have attached to this variety is in acknowledgement 

 of the exceptional courtesy shown and the assistance given me by 

 Mr. T. L. Walsh, the owner of the jDond and of the surrounding 

 land upon the mountain side. 



Heteromeyenia ryderi, v. baleni. (PI. XI, fig. iv.) 



3Ieas. Skeleton spicules 0'0072 by 0-00015 inches. Long birotu- 

 lates 0-00185 by 0-000075 inches. Diameter of disk 0-0005 inches. 

 Length of short birotulates 0*0012 inches. Diameter of its disk 

 0-0006 inches. 



Loe. Plainfield, New Jersey ; Florida etc. 



This variety bears the same relation to its typical si^ecies that v. 

 tenuis does to H. argyrosjyerma. All classes of spicules are very 

 slender; but with this exception the associated forms resemble those 

 of a. ryderi. It is dedicated to my friend Mr. A. D. Balen, who 

 first collected it near Plainfield, New Jersey ; but it has since been 

 found in several localities, including the state of Florida where it 

 was collected by Mr. Mills. 



It has been remarked in my comments upon Spongilla novce terrce 

 that intermediate forms connecting the genera distinguished by 

 birotulate spiculse, were frequent. One instance of this is found in 

 the species before us. The genus Heteromeyenia is only distinguished 

 from Meyenia by the presence of tivo dissimilar classes of birotulates. 

 The numbers of those of the larger class are sometimes so reduced 

 as to be with some difiiculty detected ; as in a form of H. ryderi sent 

 me by Prof. Osborne from Ames, Iowa. In Meyenia millsii, from 

 Florida, we have, what is essentially the same sponge, with this class 

 entirely eliminated : as, however, there is left but one class, we 

 can do no other than place that species among the MeyenicB. 



Since preparing the above, I have received two contributions of 

 sponges from Mr. Fred. Mather, the intelligent and energetic super- 

 intendent of a hatching establishment at Cold Spring Harbor, Long 

 Island, N. Y., under the care of the U. S. Fish Commission. Both 

 of tiiese have proved to be masses of H. ryderi. He reports them as 

 growing plentifully throughout the ivinter, in their tanks and ponds, 

 with the temperature frequently at 32° F. and below. The species 



