NO. 1706. CCELENTERATES FROM LABRADOR, ETC.—BIGELOW. 315 



That the pockets are primarily radial in all the genera now grouped 

 by Maas and by myself (:09) as ^ginidae is a generalization already 

 proposed by Maas on theoretic grounds. But while it is no doubt 

 true for jEginopsis, in view of the condition in jEgina alternans 

 Bigelow (:09) in which there are only four interradial pockets, the 

 question whether it holds for the entire family must remain open 

 for the present. 



A study of serial sections of the marginal region shows that there 

 is no peripheral canal system in this genus. This fact strengthens 

 the view upheld by Maas (:09) and by myself (:09) that the presence 

 or absence of canals is of little value in classification, for while 

 jEginopsis and Solmundella lack them entirely, jEgina, to which 

 they are closely allied by the conformation both of the gastric pockets 

 and of the sense organs, has this system well developed (Maas :05; 

 Vanhoffen :08). This conclusion is o])posed to the views of Van- 

 hoffen (:08), who makes the presence or absence of canals a feature 

 of prime importance in classification. 



The structure of the sense organs is of interest, since they have not 

 been described previously in this' genus. The otocysts are of the 

 ordinary teginid type (pi. 32, fig. 6), containing from 1 to 3 large 

 otoliths'and situated on prominent pads of the marginal ring, without 

 otoporpse. Since the latter organs do not occur, so far as known, in 

 any of the ^ginidse, their absence is to be regarded as an important 

 character. In the smallest individual there are sixteen otocysts, 

 two in each octant. In older specimens octants were observed 

 with three and with four otocysts, the latter number being the 

 largest counted. The greatest number of otocysts in any one indi- 

 vidual was twenty-six, in a specimen 7 mm. in diameter. Curiously 

 enough in the largest specimen, 13 mm. in diameter, with mature 

 gonads, there are only sixteen otocysts, two in each octant. 



Gonads. — In the mature specimen, the only individual in which 

 gonads are present, the sexual products, various!}^ and irregularly 

 lobed, occupy most of the surface of the gastric pockets (pi. 32, fig. 5). 

 In the quadrant figured they overlap so much as to obscure in aboral 

 views the septa separating the pockets, particidarly in the case of 

 the one in the radius of the peronia between the two tentacles. 



The occurrence of this species on the coasts of Labrador and New- 

 foundland was to be expected since it is no doubt of general boreal 

 distribution. It has previously been recorded from various localities 

 off the north coast of Europe and from Greenland, as well as from 

 Bering Strait (Brandt). It is probable also that the record of JS". 

 mertensii (Haeckel '79) from Japan belongs to this species. 



