ART. 15 COPEPOD CRUSTACEANS OF CHESAPEAKE BAY WILSON 45 



segment the shortest. Caudal rami twice as long as wide, rounded 

 at their tips and almost parallel. Egg cases elongate-ovate in form, 

 reaching the anterior margin of the last abdominal segment. 



First antennae reaching but little beyond the center of the cepha- 

 lothorax, abruptly bent at their base and considerably tapered, the 

 second and fourth segments the longest. Second antennae projecting 

 beyond the margin of the carapace, penultimate joint wider than 

 long, much shorter than the antepenultimate and terminal joints; 

 distal corner strongly produced and armed with a tuft of stout setae ; 

 terminal joint tipped with six strong setae, four of which are genicu- 

 late, and a few short bristles. 



. First maxillae tipped with two stout spines and two setae on the 

 inner margin inside the spines; palp tipped with four setae, with a 

 well-defined lobe on the inner margin, also bearing four setae. 

 Second maxillae with two coarse setae and a tiny one between them 

 near the tip of the proximal joint on the inner margin; distal joint 

 tipped with two stout clawlike spines and two setae about as long as 

 the spines. Maxillipeds with the middle joint slightly swollen on 

 the inner margin and armed with two plumose setae ; terminal joint 

 tipped with two plumose setae, but without any curved spines. 



Swimming legs with the endopods longer than the exopods, the 

 spines on both rami slender, minutely pectinate and armed just below 

 the tip with a threadlike cilia. Fifth legs with a widened proximal 

 joint carrying a stout seta on the anterior distal corner ; distal joint 

 laminate, densely ciliate on the lateral margins, with a few minute 

 spines on the posterior margin near the tip, an apical spine accom- 

 panied by a bristle, and three spines on the anterior margin, all the 

 spines pectinate. 



Color (preserved material). — Clear yellowish white. 



Measurements. — Length of adult female, 1.65 mm.; width of 

 cephalothorax, 0.65 mm. 



Occurrence. — Two females were obtained in a bottom net at Sta- 

 tion E' in water 7 meters deep over a bottom of muddy sand on June 

 2, 1921; four females in a bottom net at Station W on March 25, 

 1921, in 13 meters of water over a muddy bottom; and two females 

 at the latter station in a bottom net on June 3, 1921. The first two 

 are made the types. 



Types.— U. S. N, M, No, 58563, holotype ; No, 63420, paratype. 



Remarks. — From the record just given it is evident that this 

 copepod is probably a bottom species, found in the brackish water 

 of the inner bay during spring and summer. The type species of the 

 genus, purpureus^ was found by Sars in the Christiana Fiord on the 

 Norwegian coast and was also recorded by T. Scott from the coast 

 of Scotland. 



