Haddon — Note on Halcampa chrysanthellum. Peach. 11 



Halcampa, Cfosse. 



Body elongated, cylindrical, divided into a capitulum, scapus, 

 and physa ; the mesenteries are more or less apparent throughout 

 their whole length ; except when fully extended, the body is corru- 

 gated ; physa with minute suckers. Tentacles twelve, monocyclic, 

 marginal, cylindro-conical. Disc plain ; mouth linear, slightly pro- 

 minent. British species — 



II. chrysanthellum, Peach. 



Form. — Body vermiform, extending to about ten times its dia- 

 meter ; smooth, or only secreting a mucous tube. Capitulum and 

 tentacles completely retractile ; physa large, non-retractile. 



Colour. — Column whitish, occasionally slightly yellowish or buff, 

 rarely orange ; capitulum often more or less buff-coloured ; a pair 

 of pale bracket-marks ( ) usually present below the angles between 

 the tentacles. The orange- coloured ovaries, when ripe, shine through 

 the walls of the scapus, giving it a creamy-orange colour. The in- 

 sertions of the mesenteries appear throughout the whole length of 

 the body as white lines, and the suckers appear as white dots on 

 the otherwise transparent physa. 



Disc white, pale-yellow, or pale-buff ; may be quite plain, or 

 ornamented with variable brown markings. 



Tentacles pale-buff, with five or six light or dark bars on their 

 internal aspect, of which the basal is usually straight — the second 

 M -shaped, the third V-shaped, the three (or four) upper being 

 usually more or less straight. Externally, at the base, dark lines 

 or spots are generally present. 



Size. — 30-50 mm. (1-J- to 2 in.) long, when fully extended. 

 About 3 - 5 mm. (^ in.) in diameter. 



Habitat. — In sand or crevices of rock at low water, and down 

 to 20 fathoms : S.W. England, E. Ireland, N. France, Norwav, 

 and Denmark. 



This is the only recorded British species; but last summer I 

 dredged a well-marked second species at a depth of forty fathoms 

 off the mouth of Kenmare river, a description of which will in due 

 time be laid before the Royal Irish Academy. 



Halcampa fultoni, St. Wright (Proc. Phys. JSoc, Edinb., ii., 

 p. 91, 1859), is, undoubtedly, an immature form. I obtained 

 specimens of it which were parasitic on some HydromedusEe 



