102 
GiiEviLLE, OH Asttrolampra. 
and Amoeboid bodies^ takes place^ a rush of the semi-fluid 
contents to the spot can be plainly seen before any bulging 
occurs. Whether these Amoeboid bodies possess the power of 
" eating," will be a question for future observation. 
The above remarks increase the interest connected with the 
life-history of Volvox globator, which from analogy we may 
suppose to be a zoospore-state of another existence; to which 
opinion, indeed, the results of investigations are gradually 
drawing as. 
A Monograph of the Genus Asterolampra, including Aste- 
ROMPHALus and Spatangidium. By R. K. Greville, 
LL.D., F.R.S.E., &c. 
(Communicated by F. C. S. Roper, Esq., F.L.S., &c. Read March 14th, 1860.) 
Since the publication of my paper on Diatomacese occur- 
ring in Californian guano (^Mic. Journ.^ vol. vii), some very 
interesting materials have been placed in my hands, the 
careful study of which has led me to take a different view 
than I formerly entertained, of the generic relations of Aste- 
7'olampra, Asteromphalus, and Spatangidium. The materials 
referred to consist of — 1. Soundings from the Indian Ocean, 
obtained by Captain Pullen, in latitude 5° 37' south, and 
longitude 61° 33' east, at a depth of 2200 fathoms. This 
most remarkable gathering was presented by Mr. Hilton to 
Mr. Roper, who very kindly transmitted a portion of it to 
myself. 2. A series of slides prepared from some of the de- 
posits of the United States, by Mr. E. W. Dallas. 3. A 
series of slides prepared by Professor Walker- Arnott, from 
the substance known under the name of Monterey stone. 
My investigations into the great variety of allied forms 
derived from these sources point very decidedly towards a 
union of the three genera above mentioned ; and that Aste- 
romphalus and Spatangidium will most naturally take their 
place as sections under Asterolampra. I may here candidly 
admit that, soon after the publication of my former paper, 
I became convinced that I had committed an error in adopt- 
ing, under any modification, the genus Spatangidium; an 
error which might be traced to my desire to retain, if possible, 
a genus established by so distinguished a naturalist as De 
Brebisson. For although at first sight, under a moderate 
power of the microscope^ the difference was so striking as to 
