ART. 15 COPEPOD CEUSTACEANS OF CHESAPEAKE BAY WILSON 29 



Color. — Somewhat like meadii^ with a mid-dorsal row of dark 

 sjDOts, which are brown rather than black. In formalin specimens, 

 the thickened portion of the graspino^ antenna of the male is a 

 deep blue, almost purple. No blue or bluish-green markings appear 

 anywhere else upon the body or appendages. 



Measv/rements. — Female: Total length, 3 mm. to 3.5 mm.; great- 

 est width at posterior margin of head, 1 mm.; length of posterior 

 bod}^ 0.125 mm. Male: Total length, 2.85 mm. to 3.25 mm.; great- 

 est width at posterior margin of first thoracic segment, 1.1 mm.; 

 length of posterior body, 0.5 mm. 



Occurrence. — Several females were taken in a surface net on 

 August 22, 1920, and in a bottom net on October 20, both at Station 

 C. A few specimens were also captured at the surface on the 100- 

 fathom line. 



Types.— U.S. '^.M. No. 58568, male, holotype; No. 63416, female, 

 paratype. 



DistHhution. — ^Woods Hole (Fish). 



Remarks. — Though this is probably a pelagic species, it comes into 

 Woods Hole in considerable numbers during summer. It was ob- 

 tained there in the tow during the summer of 1923, associated with 

 meadii. It evidently enters Chesapeake Bay in a similar manner, 

 since Station C is at least 20 miles inside the mouth of the bay, and 

 there is no reason why it should not be found elsewhere in the outer 

 bay. At first sight it might be supposed that the long chitinous 

 streamer would hinder the activity of the female as compared with 

 that of the male, or even with other copepods not thus burdened. 

 But we do not find this to be true ; the movements of the female are 

 fully as energetic, and the resultant locomotion is as graceful and 

 agile as if the body were without these chitinous outgrowths. It 

 is very difficult to think of any way in which such outgrowths could 

 be useful or protective to the copepod that bears them. 



PSEUDOCALANUS ELONGATUS (Bosck) 



Clausia elongata Boeck, Christiaiiia Videuskebeliger Selskabet Forhandlinger, 



p. 234, 1864. 

 Pseudocalanus elongatus G. O. Saes, Crustacea of Norway, vol. 4, p. 20, pis. 10, 



11, 1901. 



Occurrence. — Universally distributed, but did not appear at 12 of 

 the stations, 7 of which were in the inner bay. Taken oftener at the 

 surface, but present sometimes in the bottom and vertical nets. A 

 winter form in the outer bay and a spring form in the inner bay; 

 present also in the ocean outside the bay. 



Remarks. — Sars's statement that the most southern place where 

 this s])ecies has been observed was the northern coast of France, lati- 

 tude 48° N., mu^t now be extended to 37° N. Fish found the young 



