70 PROCEEDIlSrGS OF THE NATIONAL MUSEUM. vol.60 



stout claws of about the same size standing side by side and slightly 

 curved, and a large spatulate lamina, dorsal to them and standing on 

 its edge Avith its flat side next to the claws. 



The first four pairs of legs are biramose; in the first three pairs 

 the endopods are distinctly three- jointed, wdiile the exopods are 

 indistinctly jointed, but the arrangement of the spines and notches 

 on the lateral margins show that they are also three- jointed. Both 

 rami of the fourth legs are indistinctly jointed, but again the spines 

 and notches indicate that the exopods are three- jointed, while the 

 endopods are only two-jointed. The basal portion of each foot con- 

 sists of two joints imperfectly separated. The fifth legs consist of 

 a semicircular flap on either side of the fifth segment, tipped with 

 three small spines. Just in front of each fifth leg is a single spine 

 standing out at right angles to the surface. In most females the 

 rudiments of a sixth pair of legs may be seen on the genital segment 

 behind the bases of the egg tubes. These are much more in evidence 

 in young females, where they are fully as large as the fifth pair. 



Color a dark brown or black, the brown due to the long and irregu- 

 lar ovaries, the black to the contents of the intestine. The eggs 

 are also dark brown, so that the copepod shows plainly against the 

 red background of the gills. 



Total length, 2.40 mm. Carapace 0.50 mm. long, 0.40 mm. wide. 

 Length of thorax, 1.70 mm. ; of abdomen, 0.33 mm. ; of egg strings, 

 1.30 mm. 



Internal specific characters of female. — The esophagus enters the 

 stomach near its anterior end and on the ventral surface. The 

 stomach is not much enlarged and passes insensibly into the intes- 

 tine posteriorly. The ovaries are situated in the posterior part of 

 the cephalothorax near the dorsal surface. The oviducts are more 

 or less convoluted, and when mature fill nearly all the space between 

 the digestive canal and the body wall. The cement glands are in the 

 dorsal portion of the genital segment and extend forward into the 

 fifth segment. Each is slender, club-shaped with the swollen end 

 anterior, and distinctly segmented. The semen receptacle is in the 

 posterior portion of the genital segment, ventral to the oviducts and 

 cement glands. The large maxillipeds have a correspondingly large 

 set of powerful muscles, which are attached to the dorsal surface 

 and sides of the cephalothorax. 



Nauplius. — The nauplius is ovate in outline, slightly wider ante- 

 riorly, the length about twice the width, the margins very evenly 

 curved. The plumose setae on the first antennae are longer than the 

 appendages themselves, on the other two pairs they are about the 

 same length as the appendages. The endopods of the second an- 

 tennae and mandibles have five setae, the exopods two. The bal- 

 ancers are close to the posterior end of the body, are very narrow, 



