PLANKTON OF THE GULF OF MAINE 245 



All but two of the records are inshore from the general 100-meter contour — 

 that is, off Boston Harbor (stations 200S9, 10488, and 10505, April 5 and December 

 29, 1920, and March 5, 1921); outer part of Massachusetts Bay (station 10323, 

 October 1, 1915); near Chatham, Cape Cod (station 10336, October 26, 1915); near 

 Mount Desert Island (station 10286, June 14, 1915), and on German Bank (station 

 10271, May 6, 1915) — but one of the stations of record lies in the central part of th e 

 basin (station 20114, April 17, 1920) and another outside the 100-meter contour off 

 Cape Cod (station 20116, April 17, 1920). The locations of the several locality 

 records are not such as to suggest that the specimens in question had been swept up 

 from the bottom by some current, for most of them are in regions where vertical 

 currents are comparatively weak; and it is significant that M. ignea was not taken 

 at any of the stations where the surface tows contained sand brought up by active 

 stirring of the whole column of water. It may therefore be concluded that in the 

 Gulf of Maine this copepod is regularly planktonic in small numbers; but judging 

 from its habitat in other seas it is also to be expected on the bottom in shoal 

 water, and probably in greater abundance. 



The data of capture point to the upper 100 meters as the habitat of this species 

 where it is planktonic, probably because this covers the normal depth zone of the 

 stock living on the bottom, some of which take to a pelagic life. It will be noted, 

 however, that none of the surface hauls made during the spring of 1920 took it, this 

 negative evidence suggesting that it is more apt to be at some little depth than 

 close to the top of the water. No observations have been made on the breeding of 

 this species. 



Mecynocera clausi J. C. Thompson 



Dr. C. B. Wilson contributes the following note on the general geographic range 

 of this species: 



The original specimens were obtained near the Canary Islands and at Malta, to which localities 

 Giesbrecht (1892) has added Naples and the tropical Pacific from the surface to a depth of 1,000 

 meters. Thompson and Scott (1903) reported the species from the Red Sea and throughout the 

 Indian Ocean, Wolfenden (1905) among the Maldive Islands, and A. Scott (1909) in the Malay 

 Archipelago. Wheeler (1901) obtained a single specimen from the Gulf Stream 70 miles south 

 of Marthas Vineyard, and Esterly (1905) found the species at San Diego on the Pacific Coast. 

 Esterly's specimens were taken on December 30, while Wheeler's were captured July 25. It is thus 

 very widely distributed but does not seem to occur anywhere in any but small numbers. This, 

 coupled with its small size, makes it of practically no economic importance. 



Except for Wheeler's specimen just mentioned, this species had not been taken 

 anywhere along the Atlantic coast of North America, hence its presence at three 

 stations in the Gulf of Maine in September, 1915 — one near Cape Elizabeth on the 

 20th (station 10319) and two in Massachusetts Bay on the 29th (stations 10320 and 

 10321) — is interesting as extending its known range. 



Metridia longa (Lubbock) 



This brilliantly phosphorescent copepod is a true Arctic species, though its distri- 

 bution in the Gulf of Maine suggests that Farran's (1910, p. 70) characterization of 

 it as "probably the most typically arctic copepod of whose distribution there is any 

 accurate knowledge" needs some modification. Except for one record from the 



