42 THE VOYAGE OF H.M.S. CHALLENGER. 



The structure of the peduncle is the character by which this genus is distinguished 

 from Pedicellina. The pedicel is rigid and chitinous throughout, and depends for its 

 motion on the muscular fibres which line the barrel-shaped expansion at the base ; the 

 central cavity of this expansion as well as of the rest of the stem being filled with an 

 extremely delicate parenchymatous tissue. 



The anatomy of the polypides appears to agree almost entirely, as far as I have been 

 able to observe it in the spirit specimens, with the very careful descriptions given by Dr. 

 Nitsche in his paper on Pedicellina echinata} The whole polypide or calyx is enveloped 

 in a delicate transparent membrane or ectocyst, fined with a more or less distinct tesselated 

 epithefium. The alimentary canal consists of an oesophagus, stomach, intestine and 

 rectum (PI. IX. fig. 6); the liver cells extending along the upper side of the stomach 

 present the usual deep yellow colour. In all the specimens that I have examined the 

 rectum lies in a horizontal position forming an angle with the rest of the intestine ; 

 whether this is its normal position, as it appears to be in the closely aUied genus 

 Urnatella ^ or whether it merely is the case during a young stage of growth, as mentioned 

 by Dr. Nitsche, I am unable to decide. I have not been able to observe with any certainty 

 the reproductive organs ; but in nearly all the polypides of one species, Ascopodaria fruti- 

 cosd, between the stomach and the base of the vestibular cavity, there are two large, round, 

 ovarian masses (PL IX. figs. 6, 8, 9), which are separated from one another by a thin 

 lamina (PL IX. fig. 9). In the other species these masses are not apparently always present. 



Mr. Hincks has suggested ^ that his genus Pedicellinopsis would properly include the 

 Pedicellina gracilis of Sars ; in this I am disposed fully to agree with him and should 

 therefore propose to include it in my genus Ascopodaria. Professor Leidy * refers to a 

 species oi Pedicellina found by him in 1859, which, from the short description given, if 

 not identical with. Pedicellina gracilis, ought also to be placed in this genus. The known 

 species therefore would be four or five, as follows : — 



(1) Ascopodaria gracilis, Sars. 



(2) Ascopodai^ia btdbosa, Hincks. 



(3) Ascopodaria fruticosa, 'Kmcks, = socicdis, Bk., MS. 

 < (4) Ascopodaria discreta, Bk. 



(5) Ascopodaria (J), Leidy. 



(l) Ascopodaria fruticosa, Hincks, sp. (Pis. IX., X. figs. 1-5). 



Pedicellinopsis fruticosa, Hincks, Ann. and Mag. Nat. Hist, ser. 5, vol. xiii. p. 364, pi. xiv. 

 fig. 3. 



Character. — Zoarium arborescent, constituted of thick, erect, chitinous, jointed, 

 branching stems, arising from tubular stoloniform fibres. The deciduous polypides (or 



1 Zeitschr.f. wiss. Zool., Bd. xx. p. 13. ' Leidy, Journ. Acad. Nat. Sci. Philad., 1884, vol. \x. p. 12. 



• Loc. cit., vol. xiii. p. 364. * Loc. cit., p. 14. 



