74 THE MEDUSAE. 



I am unfortunately unable to state certainly whether or not there is a canal 

 system, such as Maas (: 05) has described from a study of sections in the 

 " Siboga " specimens. 



Tlie color of this species is characteristic and striking, stomach and pock- 

 ets being lemon yellow, tentacles orange or pink. This is the coloration 

 described by Eschscholtz. 



A. citrea is one of the few species taken during the expedition in the 

 closing net, a specimen having been captured in the Tanner net at station 

 4672 from about 400 fathoms. It is widely distributed over the Pacific 

 (present captures and those of Eschscholtz), and was taken in the Malay 

 Archipelago by the "Siboga" expedition. 



It is probable that a specimen 5.5 mm. in diameter, taken at Station 4671 

 from between 300 fathoms and the surface, is to be regarded as a very 

 young stage of A. citrea. In this individual the radial septa between the 

 gastric pockets are deep. The interradial notches, however, are much shal- 

 lower ; in one quadrant there is a true septum ; in two others merely very 

 shallow notches such as subdivide adradially the eight pockets of adult 

 specimens of Aegina. In the fourth quadrant there is no interradial division 

 at all, but only a single undivided pocket occupying an interradial position. 



Aegina alternans, sp. nov. 

 Plate 17, Fig. 1. 



Station 4649 ; in the trawl, 2235 fathoms to surface ; 1 specimen, 40 

 mm. in diameter. 



This very interesting specimen was in fairly good condition. The bell is 

 high and rounded, its surface smooth, the marginal zone broad, the per- 

 oniae correspondingly long, and the margin only slightly incised in their 

 radii (PI. 17, fig. 1). Unfortunately the margin was too much damaged 

 to count the otocysts ; in one quadrant I observed one, in the next apparently 

 two ; but in the remaining two quadrants none were to be seen. The 

 sense organs are of the type usual among the Aeginidae, without otopor- 

 pae. By far the most important feature of this species is the condition of 

 the gastric pockets. These, as is shown in the general view (PL 17, fig. l) 

 are only four in number, interradial in position, without any trace whatever 

 of interradial notches ; the radial notches, however, are very deep. Fortu- 



