194 C. Spence Bate on the Peneidea. 
wardsw at the penultimate articulation. Telson shorter than 
inner branch of rhipidura. 
Length about 2 inches. 
Taken off Japan in about 500 fathoms of water. 
Sergestes japonicus, 0. sp. 
Like S. Kréyert, female, but has the ophthalmopod nearly 
as long as the first joint of the first antenna. Hye small. 
Length about 3 mches. _ 
Taken south of Japan, in about 350 fathoms. : 
This species has two pleurobranchial plumes attached to 
the penultimate somite of the pereion, one and a foliaceous 
plate to all the preceding, and a rudimentary mastibranchial 
plate attached to the first pair of gnathopoda. 
Sergestes diapontius, n. sp. 
Resembles 8. ancylops of Kroyer, but differs in the ros- 
trum being not horizontal, but directed upwards and forwards. 
Telson as long as the outer plate of the rhipidura. Ophthal- 
mopod as long as the first two joints of the first antenna. 
Eyes round. One of the flagella of the first pair is half as 
long as the animal, and twice the length of the peduncle. It 
differs from S. brachyorrhos, Kroyer, in having the lateral 
margin of each somite of the pleon terminating in a sharp tooth, 
and in the length of the telson. 
Length 1 inch. 
Taken in towing-net in the Atlantic. 
Genus PETALIDIUM (aeradicvov, a small leaf). 
This genus is very imperfectly known to me, owing to the 
damaged condition of the specimen. As far as I know it 
externally corresponds with Sergestes; but the structure and 
arrangement of the branchie are different. The structure can 
only be described by figures ; but the arrangement is asin the 
following Table :— 
Pleurobranehia ......5.s4.. sy palpate 
Arthrobranchia ......+.«..: 5 gee herp. Seaea) ieee 
Podobranchia...........06- 
Mastibranchia .........+.. 
De ib 2 eee 0 
Between the somites of the pereion corresponding with each 
branchial plume is an interstitial foliaceous leaf; hence the 
generic name. 
Petalidium foliaceum. 
Cervical suture well defined. Rostrum elevated into a 
