( 15 ) 
at tip. The lower angle bears a long simple bristle. Mandibular palpus 
two-jointed, second joint with three long terminal hairs and a shorter spine 
attached at basal third of anterior margin, jointed at base and directed 
towards tip of joint, like a dactyl. The maxilla and maxillary palpus are 
scarcely to be distinguished from those of C. staphylinus. 
The first maxillipeds are three lobed, the outer lobe constituting a long, 
strong claw. The second and third are about one-third as long as the first, 
and bear each one strong simple spine and one weak branched hair. The 
inner lobe is widest, about two-thirds as wide as long. The dactyl of the 
posterior maxilliped is spinous on its inner edge, and the same edge of the 
hand is ciliate and bears a short, stout, sparingly plumose bristle at its base, 
just beyond the tip of the closed dactyl. The width of this joint (the second) 
is nearly half its length. 
Basal joint of inner ramus of first pair of legs nearly or quite as long as 
outer ramus, the second wider but only half as long as the third, and obliquely 
truncate. Inner ramus of third pair of legs in male is three-jointed, the 
outer two-jointed, chelate. The finger is ovate, truncate, terminating in 
two long plumose hairs. The dactyl is linear, curved at base, and twice as 
long as finger. The inner ramus of the fourth pair of legs is about half as 
long as outer, two-jointed, basal joint short, terminal joint about as long as 
middle joint of outer ramus. The fifth pair of legs is best developed in the 
female. In the male the length is not over one-third the width. The basal 
portion bears three plumose hairs on its very broadly rounded anterior mar- 
gin, of which the innermost is longest. The outer plate is nearly orbicular 
and bears five spines on its terminal margin, of which the second from the 
internal angle is the longest. Genital plates found in male at posterior 
border of first abdominal segment, beneath, are short, slightly expanded in- 
ternally, with internal angles rounded, and externally bear three sub- equal 
bristles, jointed at base, the inner largest and strongest and semi-plumose. 
The antennae of the female are eight-jointed, extending backward to the 
first free segment. The basal joint of the fifth pair of legs is sub-elliptical 
in outline, with the basal half produced externally into a broad, triangular 
process which bears the second joint on its posterior margin. The free end 
of the basal joint bears six large plumose bristles of which the inner is 
longest. The greatest width of the joint is nearly equal to its greatest 
length. The second or outer joint is ovate, sub-truncate, spined on each 
margin, and bears four plumose bristles at tip and one at the middle of its 
outer margin. Its length is about twice its breadth. Same habitat as the 
following : 
Diaptomus sanguineus , Forbes. This species differs in some slight re- 
spects from the genus to which I have assigned it, as characterized by Claus, 
{Die Frei Lebenden Copepoden ) but not sufficiently to constitute it a new 
genus. In the male the fifteenth to eighteenth joints of the right antenna 
are thickened, the teeth of the mandible are not at all emarginate, the first 
joint of the terminal portion of the lower maxilliped is smaller than the 
others, and the right foot of the fifth pair in the male wants the inner 
ramus, which is perhaps represented by an immovable blunt spine at the 
