72 BULLETIN OF THE BUREAU OF FISHERIES. 



Very similar to the preceding species, size 18 to 20 mm.; nearly spherical in form; tentacles long 

 and feathered or pectinate; the 8 series of vibratile plates prominent. One of the commonest of our 

 early ctenophores, as well as one of the most beautiful and of a firmer texture than any others of this 

 order, making it possible to preserve fairly well specimens that have been properly killed. 



Distribution. — Chiefly northward, though common during early spring in Woods loleand adjacent 

 waters. 



ORDEB I.OHATA. 



Body ( tpressed laterally; that is. gastric plane longer than that of the funnel. Oral region with 



2 lateral lobes, and with 4 auricles. Tentacles in lateral furrows. 



Family LESUEURIII>.L\ 

 Marginal lobes somewhat rudimentary, auricles long and ribbon-like. 



LESUEURIA M. Edwards (1841). 

 Lesueuria hyboptera A. Agaasiz i 1865). 



Legiu iiri'i hyboptt ra A. Agassiz, North American Acalephse, 1865, p. 23. Chun, Die Ctenophoren der Plankton-Expedition, 

 1898, p. 22. 



Body large and nearly rectangular as viewed from the broad aspect. Aboral pole deeply pitted 

 with sensory body at its bottom. Very transparent and highly phosphorescent. Somewhat like 

 Mnemiopsis, though distinguishable by the greater flattening and by the rectangular aspect. 



Distribution. — Newport, K. I., Woods Hole. Massachusetts Bay. 



Family BOMNID/E. 



i.olies of medium size, auricles short. 



BOLINA Mertens ( 1833). 



Bolina alata L. Agassiz. 



Bolina alata 1. Agassiz, Memoirs American Academy Arts and sciences. Vol. IV. 1st'.', p. 349. Contributions to Natural 

 History United States.Vol. Ill, I860, \> 268. A. Agassiz, North American Acalephse, 1865, |> 15. Chun. Die Cteno- 

 phoren der Plankton-Expedition, 1898, |> 22, 



Similar in general form and size to Mnemiopsis, but more distinctly compressed. 

 Described by Agassiz as one of the commonest species in Massachusetts Bay, it is, however, rather 

 rare south of Cape Cod. being seldom found at W Is Hole. 



Family MXEM1ID.-E. 



Lobes large ami arising from about the level of the funnel, which is also the level of origin 

 of the auricles, and these are long and ribbon-like. 



MNEMIOPSIS L. Agassiz | I860). 

 Mnemiopsis leidyi A. Agassiz. 



Miicminpsis leidyi A. Agassiz, .North American Acalephse, 1865, p. JO. Fewkes,. Bulletin Museum Comparative Zoology, 

 Vol. IX. p. 291. 



This is one of our largest and commonest ctenophores. specimens often measuring 100 mm. or 

 more in polar diameter by about half that width in narrow diameter. The marginal lobes are long 

 and pendulous, extending far below the mouth level. As seen in profile the outline is somewhat 

 triangular, specially when fully expanded. In contraction the lobes are curved inward, closing 

 tightly over the mouth and giving an oval outline to the animal. The tentacles are rudimentary in 

 the adult, though quite well developed in the young. Mnemiopsis is brilliantly phosphorescent, 

 emitting sudden Hashes of light when disturbed at nijrht by a dipping oar or other cause. 



( oiiuiion throughout the region, ami usually very abundant during summer and early autumn. 



