48 CTENOPHORES OF THE ATLANTIC COAST OF NORTH AMERICA 



Genus BEROE Browne, 1756. 



Beroe, Browne, 1756, Civil and Nat. Hist. Jamaica, p. 384; also, edition 2, 1789. — 

 Fabricius, 1780, Fauna GrOnlandica, p. 361. — Chun, 1880, Ctenophoren des 

 Golfes von Neapel, p. 306. — Agassiz and Mayer, 1899, Bull. Museum Comp. 

 Zool. at Harvard College, vol. 32, p. 177. — Moser, 1903, Ctenophoren der 

 Siboga-Exped., p. 20. — Benham, 1907, Trans. New Zealand Institute, vol. 

 39, p. 139. — Moser, 1908, Abhandl. Akad. Miinchen, Suppl. Bd. i, Abhandl. 

 4, p. 18, 1907; Ctenophoren der deutsche Siidpolar-Exped., Bd. 11, Zool. 3, 

 p. 153. — Maas, 1908, MMuses Exped. Antarctique Frangaise, p. 15. 



Idyia, Freminville, 1809, Nouv. Bull. Soc. Philomat., p. 329. 



Beroe, Medea, Pandora, Eschscholtz, 1829, Syst. der Acal., pp. 35, 39. 



Idya, Cydalisia, Lesson, 1843, Hist. Zooph. Acal., p. 67. 



Rangia, Idyia, Idyiopsis, Agassiz, L., i860, Cont. Nat. Hist. U. S., vol. 3, pp. 191, 

 270, 288, 296. 



Pandora, Moser, 1908, Abhandl. Akad. Munchen, Suppl. Bd. i, Abhandl. 4, p. 32, 

 1909; Ctenophoren der deutsche Stidpolar-Exped., Bd. 11, Zool. 3, p. 159. 



Pandora, preoccupied for MolUisca by Bruguiere, 1791. 



GENERIC CHARACTERS. 



Body miter-shaped, egg-shaped, or conical; extended laterally in 

 the stomodaeal axis. Mouth opening wide and ectodermal portion of 

 stomach (stomodaeum) voluminous. The polar-plate surrotmding the 

 sense-organ at the aboral pole is fringed with a row of branched papillae. 

 There are neither tentacles nor tentacular vessels. There are ciliated 

 areas upon the walls of the stomodsetmi near the mouth. The axial 

 funnel-tube which extends upward to the sense-organ, is deeply cleft so 

 that 2 lateral vessels extend upward to the 2 apical excretion-pores on 

 the sides of the pole-plate. 8 meridional vessels and 2 paragastric canals. 

 The meridional vessels lie under the 8 rows of ciliary combs ; the 2 para- 

 gastric vessels extend down the middle of the broad sides of the animal 

 and branch out in a X-hke manner near the mouth, and fuse with the 

 meridional canals of that side only, but in B. ovata the 8 meridional 

 canals may be placed in communication one with another by means of 

 an anastomosing network of side branches, thus establishing a circum 

 oral canal-system. L. Agassiz and Chun state that these anastomosing 

 vessels do not cross the narrow sides of the body, thus leaving the 4 

 meridional vessels of one broad side separated from those of the other 

 broad side; but I find that while this is true of the young, in mature 

 specimens of B. ovata from Tortugas all 8 of the meridional vessels are 

 connected by the network, which extends across the narrow sides of the 

 animal. In B. cucumis, however, the side-branches do not anastomose, 

 so that Agassiz's statement is true for this species only. 



The type species is Beroe ovata of the Mediterranean, Atlantic, and 

 Pacific. 



In Beroe ovata the side branches from the 2 oral vessels and from the 

 8 meridional canals are deep-lying and anastomose, fusing to some extent 

 with the 2 paragastric canals. In B. cucumis, however, these fusions do 

 not take place and the branches do not anastomose, and the side branches 

 are nearer the surface than in B. ovata. 



It has been pointed out by Chun that about 45 species of Beroidae 

 have been described under 8 generic names, the genera being based 

 mainly on coloration and on external form of the body. Chun, however, 

 came to the conclusion that all of these forms fall into one genus Beroe. 

 The great diversity of opinion among older authors came from a failure 



