ART. 15 COPEPOD CRUSTACEANS OF CHESAPEAKE BAY WILSON 27 



A, O, and Q in surface and bottom nets; it was also present at the 

 surface on the 100-fathom line. 



Remarks. — Wheeler obtained only a few specimens in July and 

 implied that they had been blown in from the southeast during a 

 storm. Fish also recorded it as a summer form from the Gulf 

 Stream. Its presence on the 100-fathom line at the latitude of 

 Chesapeake Bay indicates that it is a southern form that occasionally 

 gets as far north as Woods Hole. It has not thus far been found 

 in the Gulf of Maine. It was found only in the outer portion of 

 Chesapeake Bay during summer. 



PONTELLA PENNATA, new species 



Plate 1 



General characters. — This species closely resembles P. meadii, but 

 the female can be readily distinguished from any other species of the 

 genus, as well as from all free-swimming copepods, by the long 

 pennon, or streamer, borne upon the last segment of the thorax, by 

 the excessively short, 1-segmented abdomen, and by the minute non- 

 plumose setae upon the caudal rami. The male is characterized by 

 a long fingerlike process armed with spines and borne upon the 

 anterior margin of the seventeenth ° segment of the grasping an- 

 tenna. 



/Specific characters of female. — Groove between head and first 

 thoracic segment distinct; fourth and fifth thoracic segments sepa- 

 rated, fourth segment with a rounded projection overlapping the 

 fifth segment on the dorsal surface at the midline; fifth segment 

 prolonged on each side into a broad and rather blunt point, nearly 

 symmetrical. In addition to these usual lateral points this last seg- 

 ment has also two chitinous outgrowths. One of these is a thin 

 lamella standing on edge along the midline on the dorsal surface 

 just behind the projection from the fourth segment. It is crescent- 

 shaped with the concave side toward the segment, the anterior point 

 extending above the surface nearly to the posterior margin of the 

 third segment. The posterior point is shorter but extends backward 

 above the surface of the abdomen to the posterior margin of the latter. 

 Being thus located on the midline and standing vertically, it is still 

 symmetrical. The second outgrowth, however, is completely asym- 

 metrical, being attached to the dorsolateral surface of the fifth seg- 

 ment, on the right side only and close to the lateral margin. It is also 

 a thin lamina, which extends forward above the surface of the fourth 

 and third segments nearly to the posterior margin of the second seg- 

 ment. It divides opposite the groove between the third and fourth 

 segments into two parts. The portion nearest the body is short and 



■ According to Giesbrechf s numbering ; in flg. D it is apparently on the twelfth segment. 



