118 JOURNAL OF SCIENCE. 
first pair of jaws partly wanting; branchial plate narrow, almost 
lanceolate, and beset with numerous sete on the outer and 
inner margins. Feet short and robust, second and third joints 
bearing in front a sharp seta; first pair armed with a single 
strong spine at the apex of the basal joint. Post-abdominal 
lobes larger than usual, forming 2 broad 2-lobed lamine, each 
bearing 5 sete. Eye single. 
1. Sclerochilus contortus, Norman,—Carapace, as seen from 
the side, elongated, bean-shaped, higher behind than in front, 
height equal to about half the length ; extremities well-rounded, 
dorsal margin boldly arched, inferior deeply sinuated in front 
of the middle ; seen from above, compressed, ovate, extremities 
acutely pointed, width scarcely equal to one-third of the length ; 
end view ovate, rounded above, pointed below. Shell perfectly 
smooth, Length, 1-33rd inch. 
Also found off Kerguelen Island in 20-50 fathoms; off 
Heard Island in 75 fathoms. Common on the Atlantic shores 
of Europe, and north to Spitzbergen ; also in the post-tertiary 
beds of Great Britain, Ireland, Norway, and North America. 
SECTION—PLATYCOPA. 
FAMILY III.—CYTHERELLID& (G. O. Sars.) 
Valves unequal, very thick and calcareous, not notched in 
front. Antennae very large, the anterior many-jointed and 
geniculated at the base; posterior broad and flattened, 
2-branched like the feet of the Copepoda. Mandibles very 
small, with a large pectinato-setose palp. Three pairs of hinder 
limbs, scarcely pediform ; 2 anterior pairs branchial, the others 
rudimentary. Abdomen terminating in 2 very small, narrow, 
and spiniferous laminz. Ova and embryos borne beneath the 
shell of the female. 
Genus Cytherella (Jones). 
Valves elongated, flattened, thick and hard, very unequal ; 
the right much larger than the left, overlapping throughout the 
whole circumference, and presenting round the entire inner 
margin a distinct groove, into which the valve of the opposite 
side is received. Muscle-spots arranged in a curved pinnate 
series on an oblong, obliquely-placed depression near the centre 
of the shell, the depression appearing internally as an elevation. 
Spots 12-16 in number, linear-oblong in shape, and increasing 
in size toward the ventral margin. Anterior antenne very 
large, shortly setose or spiniferous, 7-jointed, the first 2 joints 
larger than the rest, and forming between them a distinct 
geniculation ; posterior antennee composed of a large, broad, 
2-articulate, and geniculate basal portion, from which arise 2 
flattened unequal branches, one 2-articulate, the other 3-articu- 
late, both beset with very numerous long sete. Labrum large, 
subglobose, giving out in front a short subtriangular process, 
Mandibles very weak, strongly inflexed at the lower extremity, 
