293 Mr. A. Hancock on the Anatomy of Oithona. 



Two specimens were found under a stone at Bar Point, Fal- 

 mouthj together with some patches of spawn deposited on the 

 surface of the stone. " When first taken," Mr. Cocks says, " the 

 iridescent appearance of the back and the tips of the branchiae 

 was dehghtful." The tentacles were not carried erect, but pro- 

 jected horizontally " like the horns of a bull." The spawn was 

 of a hemispherical form, composed of a broadish band of ova 

 disposed in a single coil, and curved inwards above. 



Unfortunately these beautiful creatures were killed during the 

 first night after their capture by having been accidentally placed 

 in a bottle that had contained quinine, and we thus lost the 

 opportunity of seeing them in a living state. 



Anatomy of Oithona, by Albany Hancock. 



The anatomy of this animal amply proves its generic distinct- 

 ness. Unfortunately we have not been able to go very minutely 

 into the subject, having dissected only one of the two individuals 

 captured ; the other being preserved for external identification. 

 We have, however, ascertained all the leading features with suf- 

 ficient accuracy, and therefore confidently give the following 

 account of them. 



The tissues of Oithona are very tough and firm when compared 

 with those of the other Eolidid(B, particularly the skin and the 

 cellular tissue uniting the viscera. Of course we are now speak- 

 ing of the animal, after having been subjected to the hardening 

 action of spirit. Doto fragilis is the only species, with which 

 we are acquainted, that at all approaches to it in this respect. 

 The branchial papillae, too, are much more firmly attached than 

 usual, and require considerable force to remove them. 



The oral orifice is situated in the inferior surface of the head ; 

 it is small, and the external lip is divided behind on the median 

 line much as in Eolis. The channel leading to the buccal appa- 

 ratus is very short and constricted; and, just before it opens into 

 that apparatus, receives on either side below, a very slender duct 

 from a large, much foUiculated, salivary gland (PI. IX. fig. 7c,c). 

 These glands lie beneath the stomach and extend almost half- 

 way down the body. That on the right side is considerably less 

 than the other, and is somewhat tubular, — distinctly so towards 

 its termination ; the one on the left side is much complicated in 

 form, being irregularly and extensively sacculated. The position 

 of these glands is unusual : Doto fragilis is the only other species 

 in which they open into the channel of the mouth in advance of 

 the buccal mass. 



The buccal mass (PI. X. fig. 1 « & PI. IX. figs. 4, 5) is small, 

 rather long, slender, and irregularly elliptical, the corneous 

 plates or jaws (PI. IX. fig. 5 c) being visible at the sides: it is 



