168 Miscellaneous. 
is due to Reeve. I suppose we shall have to record the O. aquatilis, 
Reeve, as the O. auricularia, Lam., unless we should find a figure of 
this shell in some early work under another name. 
The only shell remaining is the 0. auricularia, D’Orb. Both 
Deshayes and Duclos are of opinion that D’Orbigny made some mis- 
take: I am of quite the contrary way of thinking. We have the 
animal and shell given, the latter differing essentially from the O. 
auricularia, Lam.; and D’Orbigny might easily have thought it 
might belong to that variable species, as it was then supposed to be. 
I cannot think that such a naturalist as D’Orbigny would figure an 
animal and put an imaginary shell upon it; and therefore I conclude 
that the shell figured is the one dredged, and no other. Having 
arrived at this conclusion, and having carefully compared the shell 
figured with O. biplicata, Sow., there is no doubt in my mind of its 
being entirely new. In the first place, its open spire is sufficient to 
prevent its being mistaken for O. auwricularia, and it differs from O. 
biplicata in not being biplicate but multiplicate, in not having the 
violet interior and basal band, and in having the basal band spotted 
—characters by which it may at once be distinguished from that 
species. 
I think the species might be named after its discoverer, 0. Orbignyt. 
2 Pevyeril Terrace, Edge Lane, Liverpool. 
July 17, 1868. 
On a Viviparous Sea-Urchin. By Dr. E. Grune. 
Our knowledge of the sexual conditions, reproduction, and develop- 
ment of the Sea-Urchins hitherto extended only to the fact that 
there are produced from the fecundated ova bilateral free-swimming 
larve furnished with lines of cilia (Pluteus), and that internal buds 
are formed in these, and become developed, in accordance with the 
5-rayed type, with a spiny test and feet, into sea-urchins, which 
acquire male or female genitalia. The semen and ova issue through 
several small apertures situated at the summit of the test near the 
madrepore-plate. 
The little Sea-Urchin upon which I have the honour to report to 
the Academy enlarges our knowledge of the natural history of the 
Echinoida by a very singular character: it produces living young, 
which are already sea-urchins, provided with test, spines, and feet, 
and so large that their diameter is more than one-tenth of the length 
of the parent animal, to which I give the name of Anochanus. 
In its appearance Anochanus most closely resembles the Nucleo- 
lites (Echinobrissus) epigonus lately described by Dr. von Martens ; it 
has an oval test, not broader behind, of 9-5 millims. in length, with 
a pit descending in the hinder interambulacrum, in which the anus 
opens, and a subyentral peristome of elongate-oval form; but the 
feet run in uninterrupted rows from the peristome to the summit, 
which nearly occupies the middle. But the most peculiar circum- 
stance is that we seek in vain for genital openings and a madrepore- 
