302 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



I have already maintained that the subfamily Eireninae, adopted 

 by Mayer, can not be sharply defined from the Eucopidae sensu 

 strictu; because one of the latter, Phialopsis comata, may show 

 the rudiments of a peduncle at maturity. There is good reason to 

 believe that Eirene, Phortis, Eirenopsis, and Tima form a natural 

 group. And though the phylogenetic relationships between them are 

 not yet altogether clear we can fairly assume that Eirenopsis is an 

 offshoot, through radial reduplication, of some Eirene or Phortis. 



Inasmuch as the character which separates Eirene and Phortis, 

 presence or absence of cirri, separates two groups, each composed of 

 several closely allied species, there is every reason to follow Mayer 

 (1910) and Vanhoffen (1912), and recognize both genera. 



The following described species belong to Phortis: gibbosa Mc- 

 Crady, pyramidalis L. Agassiz, lactea Mayer, palkensis Browne, 

 ceylonensis Browne, kambara Agassiz and Mayer, elliceana Agassiz 

 and Mayer, and pellucida Will. The latter has had a checkered 

 history. By Haeckel, by Maas and by me (1909a) it was classed 

 as a probable synonym of Eirene viridula, while Mayer (1910) 

 classed it as the young of Tima. But recent studies by Hartlaub 

 (1909), Vanhoffen (1911, 1912), and by Neppi and Stiasny (1913) 

 show that neither of these views was correct, as is gracefully ac- 

 knowledged by Mayer (1910), but that the pellucida described by 

 Claus (1881), which lacks cirri, is a perfectly distinct species of 

 Phortis, while the pellucida of Haeckel, which had cirri, is probably 

 a synonym of Eirene viridula. According to Vanhoffen (1912) the 

 genus Irenopsis of Goette, with six canals, is merely a sport of Phortis 

 pellucida. 



Unfortunately no figure of the adult P. gibbosa has ever ap- 

 peared. But this species is very closely allied to pyramidalis, which 

 is well described and figured by Mayer (1910), and of which I 

 myself studied a large series including a wide range of develop- 

 mental stages. According to Mayer (1910, p. 300) gibbosa is "dis- 

 tinguished from pyramidalis by its high bell, few tentacles, reddish 

 color, and large stomach." But the difference in form is very slight, 

 for I have myself seen pyramidalis as high as broad ; the difference in 

 tentacle number is apparent rather than real, for I have counted from 

 60 to 70 tentacles in pyramidalis 25 mm. in diameter — that is, the 

 same number as is recorded for gibbosa of the same size. In large 

 specimens of pyramidalis, of 30 to 35 mm., there are often upwards of 

 100 tentacles. 



Without any figure it is impossible to tell whether the stomach 

 is really much larger in gibbosa than in pyramidalis, but judging 

 from analogy with other species it is unlikely that its size is im- 

 portant as a specific character. And the difference in color, green- 



