356 Mr. H. J. Carter on Spongiophaga Pottsi. — 
It has already been noticed (Joc. cit.) that Mr. Potts kindly 
sent me anew or undescribed species of Spongilla affected with 
one of Spongiophaga, which, to commemorate the circumstance, 
T have named after him Spongiophaga Pottst, leaving the new 
species of Spongilla to be described by himself hereafter. ‘This 
came from a small stream in the Centennial Grounds at Phila- 
delphia; while Mr. Potts also states in his letters that he had — 
received another of the same kind from Bethlehem, situated 
about fifty miles N.N.W. of this city, and a third is mounted 
in two of his slides affecting a specimen of Meyenta (Spongilla) 
Baileyi, Bk., from Buffalo, Lake Erie, to which I shall more 
particularly allude hereafter, as it only presents an initial de- 
velopment of the filament. Meanwhile the following may be 
taken as adescription of Spongiophaga Pottst so far as I have 
been able to learn from ample fragments of the new species of 
Spongilla affected with it, together with its statoblasis, as 
arranged by Mr. Potts on four slides, viz. three mounted in 
balsam, of which two are stained red, and the fourth in glyce- 
rine; so that I am most satisfactorily supplied in this respect. 
Spongiophaga Pottsi,n. sp. (Pl. XVII. figs. 1-8.) 
Vermicular whiplike filaments, very long, round, and more or 
less tortuous, of which two, three, and sometimes four are at- 
tached to a tubular prolongation externally from the nipple-like 
rocess of the chitinous coat of the statoblasts, which juts out 
through the hilous aperture, in some specimens of Spongilla 
only (Pl. XVII. fig. 1). Filament uniformly diminishing in 
diameter from the fixed end—which is the, largest, viz. about 
1-900th of an inch thick, and applied to the tubular prolonga- 
tion mentioned just before its open termination (fig. 1,99 g)— 
to the free end, which is almost immeasurably minute 
(fig. 2,7, m). Colour transparent oil-yellow. Consistence (in 
the marine species) soft, glutinous, and elastic, but extremely 
fragile on account of its great tenuity ; so that in water, when 
once touched with a needle it so adheres to the latter that 
it is seldom disunited without fracture; yet drying en masse 
into a tough, fibro-membranous texture tearing like parchment. 
Proximal end of the filament somewhat enlarged and so 
blended with the wall of the “ prolongation” extended from 
the process of the chitinous coat, that, both being of the same 
colour and horny consistence, the former appears to be a direct 
continuation in growth of the latter (fig. 2, £7), while the distal 
or attenuated end may be curved and pointed (fig. 2, 2), or 
bilobate with a curved point between the lobes (fig. 2,0), but, 
as before stated, is almost immeasurably minute; filament 
presenting a comparatively broad cavity at its union with the 
