Chap. II. CTENOPHOR.^ LOBAT.^. 201 



have no doubt resjiecting the generic identity of these three species, to which 

 BoHna hibernica Patters, ninst be added, probably as sjTionyme of Sars'.s Mnemia nor- 

 vegica. The form of Bohna elegans Mert. does not differ at all from that of 

 Bolina alata, but there are generic differences between them, the coiu'se of the 

 chymiferous tubes in the lobes of the tropical Bolina elegans being different from 

 that of the northern Bolina alata and allied species, and the surface jDapillate, as in 

 Leucothea, Chiaja, and Eucharis. But whether Leucothea^ formosa Meii., Alcinoe 

 papillosa Delle Chiaj'e, and Eucharis multicorrds Esch., belong to this or the next 

 fiimily, I am unable to determine, as the connection of the lobes with the sphero- 

 some is not accurately described. Again, Leucothea differs in having a complicated 

 tentacular apparatus, which is simple in Eucharis multicomis. I beheve Gegenbaur 

 to be correct in assuming that Eucharis Tiedemanni Esch. differs geuericaUy from 

 Eucharis multicornis ; and that the latter is identical with Alcinoe papillosa, for 

 which Lesson has proposed the generic name of Chiaja, so that Alcinoe papillosa 

 should Ije called Chiaja multicornis,^ and the name Eucharis retained for Eucharis 

 Tiedemanni. 



Gegenbaur has questioned the validity of the genus Bolina, and believes it to 

 coincide with Mnemia. I believe he is mistaken in that respect. Mnemia has 

 not the fonn of Bolina, but coincides with Alcinoe Rang in the structure of its 

 lobes, which are not simple prolongations of the actinal side of their spheromeres, 

 but rise as lateral folds above the actinal pole of the sjiherosome, and overlap 

 the lateral spheromeres. On that accouiit, I do not hesitate to consider the genera 

 Alcinoe and Mnemia as belonging to a distinct family, for which the name of MxE- 

 jiin).E must be retained, and to which the genera LeSuemia and Eucharis proper 

 may also belong. Beroe costata Reyn. probably foiTUS another genus of this family. 

 The prolongation of the external row of flappers of the auricles, in the direction 

 of the al^actinal pole, along the furrows which separate the lobes of the spherosome 

 from the lateral spheromeres, seems characteristic of this family. I have observed 

 nothing of the kind in Bolinida?. 



I .shall retain the name of C.iLrMMiD.E, applied by Gegenbaur ^ to the whole sub- 



^ Most writers erroneously call this genus Leuco- ceived at our university library, I did not know of 



thoe. Jlertens gave- it the name Leucothea. Slilne-Edwards's earlier investigations upon the same 



" As this page came up from the printing-office, subject when I pubUshed my paper on the Beroid 



I noticed that I had not alluded to a very inter- Medusa; in 18-50, and had almost missed an oppor- 



esting paper by Milxe-Edivards, Note sur I'appareil tunity of referring to this later communication, which 



gastro-vasculaire de quelques Acalephes Ctenophores, I shall have to quote frequently hereafter, 

 published in the Annales des Sciences naturelles, ' Gegenbaur writes Calymnidse ; but, the name 



4e serie, vol. 7, p. 28-5. Owing to the irregularity being derived from Calymma, should be spelled 



with which this important periodical has been re- Calymmida?. 

 VOL. in. 20 



