516 SUMMARY OF CURRENT RESEARCHES RELATING TO 



number of hydra-like larvje attaclied by short tentacles to the sub- 

 umbrella, and furnished with a very long and flexible proboscis, with 

 the oral opening in its tip. These are the larvae of Cimina and are 

 parasitic ; and they obtain their food by inserting the proboscis into 

 the mouth of the Turritojpsis, and thus sucking from its stomach the 

 food which it contains. 



During the past summer both Turritoims and Cunina were extremely 

 abundant, and the author was fortunately able to trace the life-history 

 of each of them. 



The larva of Cunina is a hydra, with the power of asexual multi- 

 plication ; but instead of giving rise to medusa-buds like an ordinary 

 hydi'oid, it becomes directly converted into a medusa by a process of 

 metamorphosis ; it is a true larva and not an asexual generation, 

 although the occurrence of asexual production renders the gap between 

 this form of development and true alternation very slight indeed. 



In Cunina we have a series of this kind : — 



Egg, 



Larva — Larva — Larva, 



I I I 



Adult— Adult— Adult. 



If the larva which is produced from the egg were to remain per- 

 manently in the hydra-stage, we should have a series like this : — 



Egg, 



Hydra — Hydra — Hydra, 



I I 



Medusa — Medusa ; 



and such a history would be a true alternation. 



Hydro-medusae ■without Digestive Organs. * — Dr. Lendenfeld 

 describes a new sub-family of hydroids, Eucopellince, in which the 

 medusa has no digestive organs, and lives only a short time after its 

 escape from the gonophore. Only one species, Eucopella campanularia, 

 is known, and this is found in Australia. The larva is a campanularian 

 whose hydranths are carried upon short, unbranched stems, which 

 spring from a creeping root. The medusa has a veil, well-developed 

 marginal sense-organs, radial and circular chymiferous tubes, and 

 large reproductive organs, but it has no mouth, stomach, or tentacles. 

 It discharges its reproductive elements within twenty-four hours after 

 its liberation, and it lives only about thirty-six hours. 



Phylogeny of the Siphonophora.t — Professor C. Glaus treats of 

 the relation of Monophjes to the Diphyidas, and of the phylogenetic 

 development of the Siphonophora. Nine years ago he pointed out 

 that Monophyes might be compared to that larval stage of the 

 Diphyidse in which there is only one nectocalyx developed, at the 



* Zool. Auzeig., vi. (1883) pp. 186-9. 



t Arbeit. Zool. Inst. Wien, v. (1883) pp. 15-28. 



