182 C. Spence Bate on the Pencrdea. 
Tn the male the species may readily be recognized by the 
petasma being folded in a form much resembling that of an 
anchor, of which the flukes fall laterally over the basal joint of 
the two posteror pairs of pereiopoda. In the female the ventral 
plate (of a somewhat hexagonal form) lies between the base of 
the penultimate pair of pereiopoda, behind which a cup-like 
depression exists. 
Peneus telsodecacanthus, n. sp. 
Carapace with five teeth on the rostrum and one distant on 
the gastric region. Sixth somite of the pleon produced to a 
small dorsal carinate tooth. Eyelarge. ‘Telson long, pointed, 
armed on each side with five articulating spines. 
Length 3 inches. 
Taken in the channels of the Japanese islands in from 8 to 
10 fathoms of water. 
Penceus serratus, n. sp. 
Rostrum slightly arched, serrated with twelve or more small 
teeth between the apex and the frontal margin, and one more 
conspicuous on the gastric region. Lower margin ciliated, 
each hair having a defined point of attachment. Telson long, 
narrow, and pointed, laterally armed near the distal extremity 
with a rigid tooth on each side. 
Length about 4 inches. 
Taken off the Fiji Islands in about 300 fathoms of water. 
The specimens of this species are much damaged: the 
flagella of the first pair of antenne are not perfect ; but they 
appear to be slender and not longer than the peduncle. 
In other respects this species closely resembles that which 
M. A. Milne-Edwards has named Pencopsis serratus, from a 
specimen taken in the Gulf of Mexico, but which has the 
flagella of the first pair of antenne longer than the carapace, 
for which he proposes to make 4 new genus, Pencopsis. I 
have not yet met with any specimens in the collection of 
the ‘Challenger’ corresponding with this definition, that do 
not belong to the genus Solenocera of Lucas; so that I 
have not had an opportunity of examining the branchial 
apparatus to feel quite certain that the genus is a good deter- 
mination; I have therefore used the same specific name, to 
show their close approximation of form. 
Genus Pen zopsis, A. Milne-Edwards, MS. 
Like Penceus, but with the flagella of the first pair of an- 
tenn longer than the carapace and cylindrical. 
. 
