GrevillEj on Neio Diatoms. 
81 
A splendid and well-defined species^ witli four circular_, not 
very prominent processes^ placed just within the broad mar- 
giuj which is furnished with a circle of numerous obtuse teeth. 
Within this margin or border is a narrow, irregular, some- 
what dark line, apparently indicating a sudden depression of 
the surface between it and the marginal border. Hexagonal 
cellules 6 in -001^^ 
BiDDULPHIA. 
Biddulphia ChinensiSj n. sp., Grev. — -Large; frustules 
quadrangular ; valves with the angles terminating in short, 
slender, obtuse, curved processes, and with a long stout spine 
springing from the swollen base of each process. (PI. IX, 
fig. 16.) 
Hab. Harbour of Hongkong; J. Linton Palmer, Esq. 
A very fine diatom, with the colour, structure, and fragility 
of Biddulphia Mobiliensis (B. Baileyi, Sm.). At first sight 
the general resemblance is so striking that the observer might 
be excused for at once pronouncing it to be a large state of 
that species ; and, considering the notoriously variable cha- 
racter of the valve in some Biddulphi<E, it w^ould require very 
decided differences to separate it. I am, indeed, bound to 
confess that I have been deceived for a time by variations 
from normal forms in this genus, and, for example, that I am 
now convinced that my B. Roperiana is nothing more than 
one of the endless varieties of B. aurita. Nevertheless, in 
the case now under consideration, I venture to assume that 
really good diagnostic characters exist. Of B. Mobiliensis 
Mr. Ealfs remarks (Pritch. ^nfusor.,' p. 851, 1861) : "There 
is no central projection of the valves, but two slight eleva- 
tions, furnished with one or more bristles, and dividing the 
margin into three nearly equal portions. The elevations 
appear to be situated between the processes, but are really 
placed on opposite sides. This description is well illustrated 
in Smithes ^ Synopsis,^ vol. ii, pi. Ixii, fig. 322 (front view) ; 
and in Uoper^s excellent article " On the Genus Biddulphia 
and its Affinities,^^ in ^ Trans. Mic. Soc./ vol. vii, PI. I, figs. 
8, 9 (side views of valve) . Now, in B. Chinensis this relative 
position of the bristles or spines with the processes is com- 
pletely changed. The former do not divide the margin into 
three nearly equal portions, nor, indeed, divide it at all, nor 
are they situated on the margin. They arise from the swollen 
base of the processes themselves, on the inner side ; so that, 
instead of being margined, they may be said to be actually 
on the median line (an imaginary one drawn betweeii the 
