386 bulletin: museum of comparative zoology. 



appear long before mature size is attained. Such considerations, 

 do not necessarily invalidate hyalina as a distinct species, but they 

 certainly indicate the desirability of further study of it on more 

 extensive material. 



The second group, with branched gastric canals, includes ovata, 

 forskalii, and clarkii. My own studies entirely support Chun 

 and Moser in the view that the first two are easily separated 

 both by general form, which is constantly different, by differences in 

 the meridional and gastric canal-nets, and, most important, in the 

 location of the gastric products, which are arranged in diverticula 

 from the canals in forskalii, instead of in continuous bands, as in 

 ovata. B. clarkii has recently been redescribed and figured by 

 Moser. According to her (:09, p. 158), it is "kenntlich an der Form 

 und an der charakterischen Verteilung der Rippen auf der Korper- 

 oberflache"; that is to say, it is unusually broad, slightly constricted 

 just above the wide mouth, and the subventral ribs are much closer 

 together than the subtentacular, which are curved. The largest 

 specimen was upwards of 16 mm. long, the smallest 2-3 mm. There 

 is another recently described Beroe of the ovata type, B. shakespeari 

 Benham ( : 07) from New Zealand, which agrees with Moser's account 

 of clarkii in form, in the shortness of its ribs, and in the fact that near 

 the aboral pole the subventral ribs lie close together. The only 

 difference, besides size (the specimens of shakespeari were from 27- 

 62 mm. high), was that in shakespeari the mouth was small, instead of 

 large. But, as I have myself observed in cucumis, the mouth may 

 or may not be contracted by preservation. In short, clarkii and 

 shakespeari are undoubtedly identical, and probably represent, 

 not a distinct species, but a variety of ovata, with which they agree so 

 far as the arrangement of sex-products and branching of the canals 

 is concerned and Mayer ( : 12) unequivocally unites them with ovata. 



Beroe compacta is remarkable for the thickness of the gastric walls 

 and for having very little gelatinous substance. It is so far known 

 from one young specimen of 4 mm. only. Further details as to the 

 canal system would be helpful. In general form it suggested a 

 Pleurobrachia, but there was no trace of tentacular apparatus. 



The genus Beroe is represented in the "Albatross" collection by 

 only a few specimens, all small; and most of them in fragments when 

 taken from the net. So far as I can determine all belong to forskalii. 

 This is an appropriate place to record two larger forskalii from Fiji 

 collected in 1897 by Mr. Agassiz. These probably were the basis for 

 B. australis Agassiz and Mayer ('99). But the label merely gives 



