38 DISCOVERY REPORTS 



Measurements of 13 specimens gave the following results: 



The specimen, 25 mm. wide (St. 446), has an uncommonly large number of radial canals in propor- 

 tion to its size. The variability is considerable, and it is remarkable that in some specimens the 

 tentacles are much more numerous than the radial canals, whereas in other specimens the opposite 

 is the case. In all the specimens the number of rudimentary bulbs is almost equal to the number of 

 tentacles. 



The size of the specimens according to the seasons is as follows: 



Month Sept. Oct. Nov. Dec. April 



Diam. (mm.) 68-95 25-120 80-110 40-125 35-100 



Thus, large as well as medium-sized specimens were found at any time within the period between 

 November and April. It must, however, be remembered that the specimens preserved give no 

 adequate impression of the stock actually present at the time. According to a note on the label of 

 St. WS 2 '82 others of this species were thrown away'. 



Distribution. Owing to confusion with other species, the distribution of A. aequorea cannot be 

 stated with certainty. It occurs in the Mediterranean, and it seems to be generally distributed in the 

 coastal waters of the Atlantic Ocean, though apparently it is rare in the tropical belt. On the east 

 coast of North America it occurs as far north as off New York, on the European coasts up to the 

 southern parts of the west coast of Norway. There are two previous records from the west coast of 

 Africa: Senegal (Ranson 1949, p. 128) and the Gulf of Guinea (Kramp 1955, p. 265). The present 

 records from the southern coasts of Africa and South America are considerably farther south than 

 any previously known. I am in doubt as to the correctness of the records from the Pacific coast of 

 North America. On the other hand, I have recently seen some specimens taken in the Persian Gulf. 



Aequorea macrodactyla (Brandt 1838) 



1838 Mesonema macrodactylum Brandt, p. 359. PI. 4. 



1904 Aequorea maldivensis Browne, p. 732. PI. 56, figs. 4-12. 



1905 Mesonema macrodactylum Maas, p. 40. PI. 8, figs. 51, 54. 



1909 Aequorea macrodactylum Bigelow, p. 174. PI. 36, figs. 5-10. 



1910 Aequorea macrodactyla Mayer, p. 333. 



191 1 Mesonema coeliim pensile Vanhoffen, p. 230. Text-fig. 21, in part. 

 1912a Mesonema coeliim pensile Vanhoff'en, p. 371. 



19386 Aequorea macrodactyla Thiel, p. 332. Text-fig. 9. 



1953 Aequorea macrodactyla Kramp, p. 294. 



1953 Aequorea pensilis Russell, p. 355. PI. 33, figs. 1-5. Text-figs. 220c, D, 225. 



