obtained during the Cruise of the ‘ Oceana.’ al 
the Mediterranean and Atlantic Ocean, and reported from 
Puget Sound in the Pacific. It was found at fifteen stations 
in this collection, from the surface to 1670 fathoms. As 
ouly careful examination can readily determine this species 
from the next, A. longiremis, some not so examined may 
belong to the latter species. 
Acartia longiremis, Lill. 
1853. Dias longiremis, Lillj. Clad. Ostr. Cop. p. 181. 
Considerably rarer than the last species, A. Clausi, being 
hitherto known only round our own coasts and in the Baltic 
and North Sea south of Greenland. The presence of a few 
small spmes on the ahdomen and a difference in the fifth 
pair of feet of this species constitute the chief difference 
between this species and the preceding, 4d. Clausi. They 
were formerly included as one species. 
Acartia discaudata, Giesbrecht. 
1881. Dias discaudutus, Giesbrecht, Zool. Anz. vol. iv. p. 257. 
A few specimens were found at a depth of 374 fathoms. 
Tt differs from the last two species in appearance by its 
rounded short furcal segments. The Baltic, North Sea, and 
our own shores have been hitherto its recorded habitats. 
Acartia centrura, Giesbrecht. 
1889. Acartia centrura, Giesbrecht, Atti Acc. Lincei Rend. vol. v. 
p. 25. 
One specimen of this rare species was taken at 810 fathoms. 
Its small terminal spines lateral to the cephalothorax easily 
distinguish it from the three preceding species. Its only 
previous record is the Red Sea. 
Mormonilla phasma, Giesbrecht. 
1891. Mormonilla phasma, Giesbrecht, F. FI. Neapel, vol. xix. p. 532. 
One of the more common species of the collection, occur- 
ring at nine stations in fair quantity at depths from 810 to 
1610 fathoms; and previously known only from a few 
specimens reported by Giesbrecht from the Pacific, and by 
T. Scott from the Gulf of Guinea. Its long, transparent, 
slender form and thin, 5-jointed, setose antenne easily 
distinguish it from any other known species. 
