BOTANY AND ZOOLOGY. ' 97 
carry the two latter also into the group of Zoantharia. These two 
species, moreover, in their regularly distributed eminences, with their 
apical perforations and vermicularly radiating channels, preserving a 
vertical relationship of structure, in straight lines, through hundreds of 
the concentric layers, show that their upper surfaces have been locally 
and regularly differentiated through individualized portions of the sar¬ 
coid mass. In other words, each eminence answers to a polyp-cell. 
The radiating channels have some reference to a septal system, which 
in S. ccespitosa comes into still more visible existence. The dia¬ 
phragms become confluent in contiguous polyp-cells, as in Dania and 
some other genera, and as becomes the case with the lamellae of Smithia 
and Phillipsastrcea. In S. concentrica we have a more degraded 
condition of the same fundamental structure. The specialization of 
the surface is visibly wanting; the septal system is only obscurely 
shadowed forth by the reticulated passages between the spongy layers; 
the common polyp mass becomes little more than a simple sarcode, 
resting on the upper surface and Ailing the subjacent interstices; and, 
finally, its low organization is further signalized by its parasitic habit 
and its tendency to flow around and attach itself to all sides of its sup¬ 
port. 
It must be admitted that such forms as have been referred to Spar- 
sispongia possess characters in common with other genera, commonly 
included among sponges, such as Chenendoporci , Lamouroux, and Foro- 
spongia and Verrucospongia , D’Orbigny; and the radiating furrows 
may even be compared with those of such solitary forms as Gnemid- 
ium rotula and mammillare , Goldf. (Petr. Germ. Tab. vi., figs. 5 and 
6), and Siphonia prcemorsa, Goldf., as figured by Hisinger (Petrif. 
Svec. Tab. xxvi., fig. 7) ; but these affinities, instead of drawing 
our Stromatoporce toward Amorphozoa, only raise the question whether 
the affiliated genera are not also sufficiently related to polypi to fall 
under a particular family of Zoantharia. 
For reasons set forth above, I should agree with Agassiz and Mc¬ 
Coy in placing the Stromatoporee amongst Zoantharia, but I should 
differ with both in deciding upon their local affinities. Agassiz seems 
to have placed them in Milleporidae, governed by the minutely vesicu¬ 
lar structure of the mass ; homologizing this with the cellular structure 
of the coenencliyma of Millepores ; while, in my own view, these corals 
are destitute of coenencliyma, and their vesicular tissue is endo-struc- 
Vol. XV. 13 
