Boone, Coelenterata, Cruises of "Ara" and "Alva" 35 



Order: LEPTOMEDUSAE 

 Family: AEQUORIDAE 



Genus: AEQUOREA Peron and Lesueur 

 Aequorea coerulescens (Bi'andt) 



Plates 5 and 6 



Type: Brandt's type was taken in the Pacific Ocean, about 

 Lat. 35° N., Long. 144° W., by Mr. C. H. Mertens, whose exquisite 

 colour plates of this species apparently furnish the only colour 

 record published. The type material is deposited in the Zoological 

 Museum at St. Petersbourg (Leningrad), Russia. 



Distribution : This exceedingly rare medusa is known only 

 from the type locality, a fragmentary specimen from the Maldives, 

 insufficient for positive identification (Bigelow, 1904), and one 

 "large" specimen, 60 millimeters in diameter, from the "Alba- 

 tross" station 4652, 100 fathoms to surface, and one specimen, 12 

 millimeters in diameter, from station 4655, 300 fathoms to sur- 

 face, off Agudas Point, Peru, and the two specimens taken by 

 Mr. Vanderbilt at Valparaiso, Chile. 



Material examined: Two specimens, taken at Valparaiso, 

 Chile, February, 1935, by the "Alva." 



Technical description: The larger specimen has a total 

 diameter of 225 millimeters, a central mouth diameter of 75 milli- 

 meters and a radius of 75 millimeters for the area between the 

 iputer margin of the mouth and the circumferal margin. The 

 smaller specimen has a total diameter of 225 millimeters, a central 

 mouth diameter of 60 millimeters and a radius of 55 millimeters 

 for the bell area between the outer margin of the mouth and the 

 circumferal margin. These specimens are extremely interesting 

 not only because of their great size, the larger one being 3.75 

 times the size of the largest one hitherto recorded (Bigelow, 1909) , 

 but because they establish the first Chilean record for a medusa 

 for which the southernmost record has heretofore been off Agudas 

 Point, Peru, (about 82° Long. W., 5° Lat. S.), thus extending our 

 fragmentary knowledge of the Leptoline Medusae fauna of the 

 tropical west coast of South America. It is significant that both 



