192 C. Spence Bate on the Pencidea. 
Gennadas parvus, i. sp. 
Rostrum short, pointed; crest armed with one tooth, and 
behind the crest a little point. Ophthalmopod short. Pereio- 
poda slender. Pleopoda long. ‘Telson short. 
Length scarcely 1 inch (male). 
Taken off Japan in 2425 fathoms. 
This small species is undoubtedly an adult male; for the 
petasma attached to the first pair of pleopoda is large and 
well developed, while two button-like plates, larger than are 
found in animals of much greater size, are attached to the 
second pair of pleopoda. ‘These are seen only in well ma- 
tured males. 
It has been taken frequently in both Pacific and Atlantic 
oceans, in from 1240 to 2550 fathoms, and once in the deep 
trawl-net in the Pacific. 
Genus EupHema, Edwards. 
There is a specimen in the ‘ Challenger’ collection which 
belongs to this genus; but I think that it is only a very 
young and immature form of some species of Peneus. It 
corresponds nearly with the figure of the fourth stage in the 
development of Palemonetes vulgaris as given by Mr. Walter 
Faxon in his plates on the development of the latter species 
in vol. v. no. 15 of the ‘ Bulletin’ of the Museum of Compa- 
rative Zoology at Harvard College, U.S., 1879, excepting 
that our specimen has the third pair of pereiopoda chelate. 
The rostrum is curved upwards, and is not denticulated 
along the margin. The large tooth upon the dorsal sur- 
face of the second somite of the pleon is waved and turned 
upwards; and the fourth, fifth, and sixth somites terminate 
posteriorly in a small tooth. 
Length little more than } inch. Edwards’s specimen is 
8 lines. 
Both were taken in the Atlantic Ocean. 
I give our specimen no name, feeling sure that it is a young 
Peneid, probably of the genus Avisteus. 
Genus PASIPH@A. 
Neither by the description of M. Milne-Edwards nor the 
figures of Risso and Savigny can this genus be retained in 
the group or family of the Penzide or allied forms. 
It the species in the ‘ Challenger’ collection belong to this 
genus, as I believe they do, the branchial plumes are deve- 
