332 Mr. II. J. Carter on Spicules of Spongilla. 
sent me by Mr. Potts, to which I have alluded, also charac- 
terize the entre specimens from the Elbe (see Dr. Vejdovski’s 
representations of the latter, op. cdt. pl. i. fig. 14, A, B, &e.), 
which seems to confirm this view still further. 
It is remarkable that, in addition to the well-known species 
of the Old World, viz. Spongilla lacustris and Meyenia fluvia- 
tilis, two other distinct ones should have been found in Cen- 
tral Europe, viz. Spongilla Cartert (previously only known to 
me in India, the Mauritius, and latterly in the island of 
Madura, on the E.N.E. coast of Java) by Dr. Thomas Margo, 
of Budapest, in Lake Balatan (‘ Annals,’ 1882, vol. x. 
p- 369), and Meyenia ertnaceus, which is the same as Mey- 
enia Leidyi, in the Spree and Elbe, by Leidy, and by Potts 
in the State of Pennsylvania, in North America. 
From what has been above stated then it would appear that 
Ehrenberg gave the name of Spongilla erinaceus to this species 
in 1846, and Dr. Bowerbank the name of Spongilla Leidyi to 
it in 1868. 
Returning to the Altmiihl-valley diluvium and that spicule 
above stated to be unknown to me, we are struck with the 
abundance of this szliceous refractive vermicular form, 
which is cylindrical and round at the extremities, but 
may be curved, inflated, sigmoid, contorted, branched, and 
indeed varied in an infinite number of such-like ways, 
below 10-6000ths inch in length and a little less in breadth 
than 1-6000th inch, which are the dimensions of the largest 
and straightest (although always somewhat curved) specimens 
that have come under my observation (fig. 18, e). Moreover 
it frequently presents itself in small groups or massive aggre- 
gations in the diluvium, wherein all the sizes and shapes 
appear together as if it grew from small to large in this way, 
and naturally existed in this condition (fig. 18, d). On 
account of its refractive character the central canal is seldom 
seen, but in one instance a central cavity was observed which 
was extended on both sides fora little distance in a linear 
form (fig. 18, £); otherwise I have not been able to detect 
any indication of its existence. ‘To what this sz/iceous spi- 
cule could have belonged I am totally ignorant, since it is 
so entirely unlike any thing of the kind connected with the 
Spongillide that I have ever seen ; yet it may be asked what 
it could come from but a Spongilla or a treshwater sponge. 
Herein lies the question; and therefore I describe and delineate 
so much of it as I know simply to call attention to the facet 
and to assist others in supplying an answer. 
4 
i. 
‘ 
; 
i 
j 
; 
