16 
Shadbolt on New Forms of Diatomacece, 
gonally, that is, with (what the Rev. W. Smith considers) 
cells placed alternately in contiguous rows. The outline of 
the largest (fig. 8) is very clumsy and the ends obtuse, and 
the median line but slightly flexed — this 1 call " validum;^ 
the other, P. inflatum, on the contrary, is of a graceful out- 
line, the apices acute, the flexure of the median line con- 
siderable, and is broad in proportion to its length (fig. 9). A 
third species is, I believe, also new ; it was observed by 
Mr. Capron when making the drawings ; but as I have not 
had an opportunity of examining it, I have not further no- 
ticed it. Specimens of P. formosiim and P. Hippocampus are 
also found. 
There are two new species of Amphitetras, viz. A. ornata 
and A. tessellata ; the former (fig. 10) is of small size, the mar- 
gins of the valves being considerably hollowed or emarginate 
and folded over so that each valve is not unlike in form to a 
collegian's cap. The surface is elegantly but somewhat irre- 
gularly ornamented with delicate markings. A. tessellata (fig. 
11) is of larger size, and the markings coarse and resembling 
a tessellated pavement. 
There is a very striking and beautiful discoid valve, toler- 
ably abundant, of the same genus as one commonly found in 
the guano from Callao, but which, I conceive, has never yet 
had a generic name. It differs in essential characters both 
from the Coscinodiscus and Actinocyclus, and its position 
would probably be midway between them. 
It is possessed of a pseudo nucleus, is minutely embellished 
with delicate markings similar to those seen in Pleurosigma 
aiiqulatum^ &c., but in segments radiating from the centre, so 
that, in all probability, the front view would exhibit slight 
undulations. The absence of any distinct division between 
the segments, however, separates it from Actinocyclus. I 
propose for this form the generic name Actinophcenia^ from 
axTiv, a ray, and ^aetvof, glittering, with the specific designa- 
tion splendens. 
Fig. 12 is a new species of Eupodiscus, having four pro- 
cesses arranged regularly, and with the markings of a some- 
what similar character to those in the last described species, 
forming an elegant cross ; I have, therefore, named it E. 
crucifer. 
Fig. 13 represents a Campylodiscus latus, also new, the cana- 
liculi being wide apart and few in number. 
Moderately abundant in this gathering are specimens of a 
highly interesting nature, on which the generic name of As- 
terolampra has been conferred by Professor Baily, of New 
York : one species, A. marilandica, has been figured in ' the 
