250 CTENOPHOR^. Part II. 



chusetts, in his Report on the Invertebrated Animals of that State, where he 

 considers it, however, as identical with the Alcinoe vermicnlaris of the coast of Bra- 

 zil. But a close examination has satisfied me, that it is neither identical with that 

 species, nor even belongs to the genus Alcinoe, but constitutes the first Atlantic 

 representative of the genus Bolina.' 



There is a marked difference between this species and Bolina septentrionalis 

 3Ieri., in the less limited development of its longitudinal diameter, in the greater 

 approximation of the two auricles of each side, and in the greater width of the 

 large lobes ; for which reason I have called our species Bolina alata. Like all 

 true Bolince, it is of a transparent bluish white. Bolina norvegica, Sars's Mnemia 

 norvegica, is at once distinguished from the species found along the north-west and 

 the north-eastern coast of America, by the sudden projection of its lobes. A fourth 

 species, which I call Bolina vitrea, occurs on the southern coast of Florida. It dif- 

 fers from the preceding ones by its greater height, the narrowness of its locomotive 

 flappers, and its extraordinary transparenc}^ I am unable to state with certainty, 

 whether Bolina hybernica PaU. differs from the species described by Sars or not. 



Bolina alata is a most delicate, transparent, and diilluent animal ; so soft that 

 it readily decomposes under the least unfavorable circumstances. The admixture 

 of a small proportion of fresh water in the bowls in which I used to preserve 

 them caused not only their immediate death, Init also their instantaneous decompo- 

 sition. All my efforts at preserving specimens in Goadby's liquor have entirely 

 f;iiled ; and when, under identical circumstances, I succeeded in keeping for a long 

 time specimens of Pleuroljrachia rhododactyla, I failed in 2)reserving specimens of 

 Bolina alata longer than twenty-four hours. Again, this species being by no means 

 so common as the Pleurobrachia, with which it is always found associated, I had 

 to contend with great difficulties in my investigations of its structure. I succeeded 

 several times, nevertheless, in injecting it with indigo ; and, though the injection soon 

 caused the death of the animal and its decomjiosition, I have been able to trace 



'It is a remarkable circumstance, that the rhododactyla, another species of the genus, de- 

 Atlantic shores of America should furnish, in lower scribed as jNInemia norvegica liy Sars, accompanies 

 latitudes, a species of the genus Bolina very similar the Pleurobrachia bicolor of the boreal fauna of 

 to that which occurs in Behring Strait ; but this Europe ; and that the Bolina septentrionalis of Mar- 

 is only one of the many instances showing that tens belongs to the same fauna with the Pleurobra- 

 species on the opposite shores of this continent are chia Bachei discovered by my son in tlie Gulf of 

 adapted to the diflercnces which exist in the cli- Georgia, where it occurs together with Bolina sep- 

 matic conditions, and the diflerent course of the tentrionalis. Jloreover, a distinct species of Idyia 

 isothermal lines on tlie eastern and western sides is also found in each of tiiese three fimna', one of 

 of the Old and New Worlds. It is also interesting which is described l>y Sars in his " Beskrivelser," 

 to notice, that while Bolina alata is, everywhere ami the other two in the following section of this 

 on our coast, found associated with I'leurobrachia chapter. 



