MNEMlOPSiS. 



19 



Bolina vitrea Agass. 



Bnlina vitrea Agass. Coiitrili. X;il. Ilisf. U. S., Vol. III. pp. 2(;!», 280, Fig. f)3. 18G0. 

 f Bolina liltnralis MrC'ii. On tlir l)iv(I(i|niHiit of two Sju-cii-s of Ctrnophorae, 18.J7 ; Proc. Elliot 

 Soc. N. II.. p. 1. 1 «.■>«. 



The Bolina Vittoral'is McCr. is proljahly eitlier this 

 species, or one of our species of Mneniiopsis ; but 

 not having the means to determine this point, a 

 ligure (Fig. 19) of the BoVuia vitrea Agass. is added 

 here, to serve as a basis for its identification here- 

 after. 



Eeef of Florida (Agassiz) ; Charleston (McCrady). 



Fip. 19. 



Bolina microptera A. Agass. 



Bolina septentrionalis Agass. (non Mortens). Cont. Nat. Hist. U. S., III. p. 289. 18C0. 



The discovery of several species of Bolinidae on the eastern coast of 

 North America, belonging to different genera, which had all been con- 

 founded together, has induced me to examine anew the descriptions 

 and drawings of the species of Bolina observed on the northwest coast. 

 1 have become satisfied that the species of Bolina here noticed is not 

 the B. septentrionalis of Mertens, but differs specifically from it. It 

 is quite elongated ; the lateral lobes are very short, with complicated 

 windings of the long ambulacral tubes. This species resembles in out- 

 line more the Bolina vitrea Agass. than any other. It has, like it, 

 a long digestive cavity, but differs from it in the proportions of the 

 lateral lobes, and the complexity of the windings of the long ambulacra. 

 It is, like the B. vitrea, perfectly transparent and nearly colorless, of a 

 slight bluish tinge ; the polar diameter measures about two inches. 

 Found in June, in the Straits of Rosario, Washington Territory. 



Gulf of Georgia, W. T. (A. Agassiz). 



MNEMIOPSIS Agass. 



Mnemiopiiis Agass. Cont. Nat. Hist. U. S., HI. pp. 26;», 290. 1860. 



The genus Mnemiopsis is remarkable among the Bolinida3 for the 

 pecidiar structure of the tentacular apparatus, which sends a branch 

 along a deep furrow, protected by a lappet, to the base of the auricles. 



Fig. 19. Rolina vitrea seen ihnn tlic hmad side. /-,/', long aniliulaera ; /*, /^ short ambu- 

 lacra ; /, funnel ; r/, digestive cavity : /. tentacular tul)c ; x'- X*' auricles ; /, /, anterior and poste- 

 rior lobes ; h', tentacle. 



