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XXV. Remarks upon Appendicularia and Doliolum, two genera of the Tunicata. 
By Thomas Henry Huxley, Assistant-Surgeon R.N. 
{late of H.M.S. ^‘Rattlesnake"). Communicated by Prof. Edward Forbes, F.R.S. 
Received February 26, — Read March 27, 1851, 
79. The genus Appendicularia was first formed by Chamisso from an animal found 
by him near Behring’s Straits, and thus described: “Corpus gelatinosum, subovoi- 
deum, vix quartam pollicis partem aequans, punctis rubescentibus (interaneis) trans- 
parentibus. Appendix gelatinosa cestoidea, rubro marginata corpore duplo vel triple 
longior. Motu flexuoso natation! inserviens. Motus animalis vividus.” And he adds, 
“genus ultra recognoscendum, generi Cestum (Les.) forsitan affine.” The specific 
name “flagellum” was conferred upon the animal, and it was figured (P. XXXI.), 
though very indifferently*. 
Ten years afterwards (in 1828) Mertens, voyaging in the same regions, rediscovered 
this animal^ and he subsequently published a long account of it'|' under the name of 
Oikopleura Charhissonis. 
The only other notice of the genus (so far as I am aware) is that given by 
MM. Quoy and Gaimard:{:. It was observed in immense masses off Algoa Bay, 
South Africa, and was called by them Fritillaria, until they afterwards became 
acquainted with the descriptions of Chamisso and Mertens. Recognising as they do 
the priority of discovery of the former, they yet adopt the name conferred by the 
latter, and, without any very just reason, give to the specimens observed by themselves 
a new specific name, O. hifurcata. 
Vast numbers of the species observed by myself were found on the coast of New 
Guinea and in the Southern Pacific. The differences separating this from the species 
observed by Mertens are not to my mind sufficient to form the basis of any specific 
distinction, and as the description given by MM. Quoy and Gaimard, and by Cha- 
misso, are too imperfect to establish any certain distinguishing characters in their 
case either, I shall consider that only one species has been observed. And as I can 
see no reason for the construction of a new and by no means euphonious name by 
Mertens, I shall retain both the generic and specific names given by Chamisso, 
Appendicularia flagellum (Chamisso), Syn. Oikopleura Chamissonis (Mertens), 
Oikopleura hifurcata (Quoy and Gaimard). 
* De Animalibus quibusdam et classe Vermium, Fasc. Secundus. Nova Acta Acad. Cur. tom. x. 1821. 
t In the Memoires de I’Acad. Imp. de St. P^tersbourg, 1831. 
J Zoology of the Astrolabe, vol. iv. p. 304. 
