Chap. II. 



LIMITS OF THE CLASS. 



109 



Fiij. 63. 



Pelagia cyasella, Per. and LeS. 

 ! a Umbrella. — m m Mouth tentacles or arms ; 

 the prolongation of the angles of the mouth. 

 — tt M;irgiual tentacles. 



It appears thus, that, wheth- 

 er originathig from Hydroids 

 or not, all genuine Gymnoph- 

 thalmata, the Diycophora? Cryp- 

 tocarptB of Eschscholtz, must 

 be united into one great natu- 

 ral division with all the genu- 

 ine Hydroids, whether these 

 produce free Medusae or not. 

 But, while I acknowledge that 

 the free Medusaj born from 

 Hydroids show their Acalephian 



Hybocodon prolifeb, Ag. 

 '. stem of a single Hydra. — o Its mouth sur- 

 rounded with tentacles. — / / Its marginal 

 tentacles. — d dd The most advanced of its 

 Medusae bud.s. 



Fig. G5. 



Fin. CO. 



Fig. 67. 



Medusa bud of 

 Hybocodon prolifer, Ag. 

 t Base of attachment to the Hydra stock. 

 . — Proboscis. — c Circular chymife- 

 rous tube. — b Radiating chymiferous 

 tube. — d t Proliferous Medusa with 

 its single tentacle. — t Single tentacle 

 of the primary Medusa. — Near c An- 

 other small proliferous Medusa-bud. 



Fig. 68. 



Cory'ne mikabilis, Ag. 

 Hydra with a Medusa bud. This 



bud when freed becomes a Sarsia, 



Fig. 70. 



a Stem of the Uyin. — v Its club- 

 shaped body. —o Its mouth.— w Ten- 

 tacles scattered over the body — d 

 Medusa bud. 



Free Medusa of 

 Hybocodon pkolifek, Ag. 

 The longest vertical tube being 

 seen in profile. 



1' Proboscis. —TO Kadiating tubes. — s 

 Circular tube. — t Tentacle. — m Buds 

 of Medusa*, proliferous from its base. 



Medusa bud of 



COBYNE MIRABILIS, Ag. 



The bud represented here sepa- 

 rately, with its base of attachment 

 a cut through, is younger than that 

 represented in its natural connection 

 in Fig. 68 d. The free Medusa is 

 represented Fig. 70, and described 

 as Sarsia mirabilis in the Contribu- 

 tions to the Nat. Hist, of the Acalephs. 

 a Base of attachment to the Hydra 

 stock. — Proboscis. — & Radiating 

 chymiferous tubes. — t Tentacles. — 

 All the intermediate forms, from the 

 youngest buds to the adult Medusa?, 

 will be described in the next volume. 



Free Medusa of 



Hybocodon prolifer, Ag. 



Facing the longest chymiferous 



tube. 



a Point of attachment before its separa- 

 tion. — be Radiating or vertical chy- 

 miferous tubes, c pointing to the circu- 

 lar tube. — t Tentacle. — / Bunch of 

 proliferous Sledusa; buds. — e Rows of 

 epithelial cells forming distinct bands 

 at the surface. — o Proboscis. 



Fir;. 70. 



The free Medusa, Sarsia, of 



CORYNE MIRAIJILIS, Ag. 

 ' Proboscis. — b Vertical chymiferous 

 tube. — c Circular tube. — e e Dia- 

 phragm. — t i Teutacles. 



