Miscellaneous. 181 
to the existence of many peculiar forms of land-shells on the island ; 
and Wollaston collected these with such zeal, that in a very short 
time he had obtained examples of a great many more species than 
had fallen to the lot of Mr. Lowe during several years’ residence in 
Madeira. A descriptive account of these shells, and of others ob- 
tained by him in other Atlantic islands, was his last completed work, 
and will, we hope, appear shortly. 
This notice has already extended to such a length that it will be im- 
possible to refer particularly to any of Wollaston’s scattered papers. 
From 1846 until last year he was a frequent contributor to our 
pages, in which many of his best papers appear. Others, of equal 
value, will be found in the Transactions of the Entomological 
Society, in the ‘Journal of Entomology,’ and in the ‘ Entomologist’s 
Monthly Magazine.’ Altogether he published about 50 separate 
papers, nearly all relating to Coleoptera. 
When we consider that for 30 years of his life Wollaston was 
always in a most delicate state of health, the amount and the quality 
of the work done by him is at first sight surprising. But it may be 
that the very weakness of constitution which all his friends de- 
plored was really to some extent the cause of his success, by 
preventing his going much into society, where his kindness and 
geniality must have made him a favourite, and compelling him to 
live for the most part in a retirement which afforded him so many 
opportunities of devoting himself to the patient and minute research 
by which, coupled with the power which he eminently possessed of 
taking broad and philosophical views of his results, his reputation 
was mainly built up. 
On the Orthonectida, a new Class of Animals Parasitic on Echinoder- 
mata and Turbellaria. By M. A. Grarp. 
The little Ophiuran, Ophiocoma neglecta, sometimes contains a 
singular parasite which may serve as the type of a whole group of 
animals of very curious organization and hitherto almost unknown. 
The following are the circumstances under which this parasite is 
met with. Ophiocoma neglecta is an Ophiuran with condensed em- 
bryogeny, or viviparous. The incubatory cavity, situated in the 
aboral part of the disk, communicates freely with the exterior; for 
the most advanced embryos contained in this cavity frequently 
present upon their arms a pretty Vorticella, which occurs almost 
always upon the arms of the parent animal. On tearing open the 
disk in order to extract the embryos from it, we find it, in certain 
individuals, filled with a multitude of animals like large ciliated 
Infusoria, which traverse the field of the microscope in a straight 
line and with the rapidity of an arrow. These animals occur of two 
forms, which I shall name provisionally the elongated and the ovoid 
form. In both they are simple planule, that is to say, organisms 
composed only of two layers of cells—an exoderm or outer layer 
of ciliated cells, and an endoderm consisting of larger cells bounding 
a linear central cavity with no buccal aperture or anus. Notwith- 
