[5] 



MEDUSA FROM THE GULF STREAM. 



931 



aud form, that I have placed them in two species. These may later be 

 generically divided when live specimens are studied. 

 The two marked diflferences in these specimens are as follows : 

 Certain of them have a brown color, with central disk and corona on 

 the exumbral side, very rough, apparently covered with coagulated 

 slime (?), and with the central disk conical and of small altitude. The 

 specimens referred to P. hyacinthma, St., have the bell walls more 

 transparent, and the purple color is seen through the bell walls. 



These differences might at first be ascribed to the state of i>reserva- 

 tion of the specimens, but this is improbable since from Station 2036 

 we have in the same- bottle two of the brown and one of the well-known 

 purple P. hyacinthina. The brown species is very much smaller than 

 the majority of the examples of P. hyacintMna. 



Periphylla humilis, sp. nov. 



specimens exaviined. 



The bell is low conical, with diameter double its height. The surface 

 of the umbrella brown, rough, opaque. The central disk and corona of 

 uniform color. Diameter of largest specimen, 18"'™, when marginal lobes 

 are expanded; diameter of central disk, 2™'". Diameter of tbe smallest 

 specimen, 8™™. 



When seen from above, the exumbrella is found to be divided into two 

 regions, separated from each other by a coronal fnrrow. The central 

 region, "zona centralis," "discus centralis," occupies the central portion 

 of the umbrella, while the "zona marginalis" bears the four marginal 

 sense-bodies and the twelve marginal tentacles. The discus centralis is 

 of low altitude, conical, sometimes nearly flat, rounded at the apex. In 

 one or two specimens the elevation of the apex is inconspicnous. No 

 apical opening was seen. The margin of the discus centralis is entire, 

 without sulci radiales. In the largest specimen large (abnormal ?) gela- 

 tinous white or translucent warts occur on its sides and outer surface. 



The zona marginalis in alcoholic specimens is carried at the same 

 angle to the vertical axis as the sides of the conical " discus centralis," 

 forming a continuation of the former, and in one or two specimens it is 

 at right angles to the vertical axis. In most of the specimens the color 

 of this region is like that of the discus centralis, although it has some- 

 times a blue and light green color. 



The zona marginalis is crossed by sixteen incisions, which extend 



