REPORT ON THE TUNICATA. 39 



and Gaimard, a species taken by himself in the South Pacific, between Sydney and 

 New Zealand, during the voyage of the "Rattlesnake." Whether this species was 

 actually the same as that found by the " Astrolabe " it is impossible to decide now on 

 account of the deficiencies in Quoy and Gaimard's description ; Ijut as Huxley was 

 satisfied as to their identity, and has given us a full description, with figures, of his 

 specimens, it seems best to adopt that description as applying to the species Doliolwn 

 denticulatnm, Quoy and Gaimard. Uljanin,^ however, while considering that Quoy 

 and Gaimard's species cannot now be determined, refers Huxley's Doliolwn denticulatuni 

 to a new species Doliolum gegenbauri, which he describes afresh (1884). This is 

 surely unnecessary. Even if it be admitted that Quoy and Gaimard's species can 

 never be determined positively, and must therefore lapse, yet Doliolum denticulatum, 

 Huxley (1851), must take precedence over Doliolum gegenbauri, Uljanin (1884), and 

 therefore the only change necessary is to substitute Huxley's name for Quoy and 

 Gaimard's as the authority for the species. 



In 1852, Krohn's^ paper dealing with the Mediterranean species of the genus gave 

 for the first time an account of some observations on the complicated process of repro- 

 duction and life-history. Although Krohn's account was in some respects erroneous, 

 still he was the pioneer in regard to this diflicult subject. He found the tailed larva, 

 and he first pointed out that there was an alternation of generations, and recognised 

 some of the leading stages in the life-history. Gegenbaur's^ observations about the 

 same time still further elucidated the matter, and both authors added considerably to 

 the knowledge of the different forms of Doliolum present in the Mediterranean. 

 Leuckart's* paper on Salpas and allied forms, and Keferstein and Ehlers''* memoir 

 on Doliolum, added considerably to the knowledge both of the structure and of the 

 embryology of the genus. 



The condition of the knowledge of species at that time (1861) was as follows ; — 

 Krohn had described four new species, Doliolum ehrenhergii (which he identified 

 with Doliolum denticidatum, Quoy and Gaimard. He changed the specific name, 

 because he found that the denticulation was common to various species. This is not 

 the same species as Huxley's Doliolum denticulatum), Doliolum, miilleri, Doliolum 

 nordmanni, and Doliolum troschelii. The last two are, however, " nurse " or immature 

 forms (blastozooids belonging to Doliolum miilleri), with nine muscle bands and a 

 dorsal outgrowth; so that only two good species were added, Doliolum ehrenhergii, 

 Krohn, and Doliolum miilleri, Krohn. Gegenbaur investigated, in addition to Krohn's 



' Fauna und Flora des Golfes von Neapel, Monogr. x. Doliolum, p. 134, Leipzig, 1884. 



- Ueber die Gattung Doliolum, &c., Arch.f. Nalurgesch., Jahrg. 18, Bd. i. p. 53. 



^ Ueber die Entwiokluiig von Doliolum, Zcilschr.f. iriss. Zool., Bd. v. p. 13, 18u4 ; and also Bd. vii. p. 283, 185C. 



* Zoologisohe Untersuchungen, Heft ii., Giessen, 1854. 



•'' Zoologische Beitriige, Heft iii. p. 53, Leipzig, 18G1. 



