Das System der Polycladen. 573 



cornua augulus acutus ex atoniis nigris compositus ; huius crura retiorsum spectaut : auticam corporis par- 

 tem iuter cornua interdum proilucit. Corpus album, supra vascuHs piiiiiatis rufis, subtus punctulis albis, 

 quasi ovulis, passim inscriptum, margo varie flexilis. — Iii sinubus littoris Christiansaudensis, inter rupes 

 Lynger, et in sinu Dröbacliieusi ; illic quatuor specimina, bic unicum semel reperi.« 



2' Doris. »Body oblong, fiat beneath, creeping. Mouth placed below. Vent bebind; surroundod 

 witb a fringe. Two feelers, retractile.« 



Doris electrina (34 ainbers;. »D. witb tbe front abrupt; body bas the appearance of a snail ; bila- 

 mellated, size of tbe figure (circa 16 mm); amber colored. Taken of Anglesea.« 



3) Erklärt mit Unrecht die Planaria vittata Mont. für synonym mit Planaria coruuta 

 (). F. Müller. Beschreibung von PI. cornuta: 



»Body oval, flat, tliiu, soft, tbe margin plane: length about three fourths of an inch ; tbe breadtb 

 about one lialf tbe lengtb. Dorsal surface reddisb brown , freckled witb white dots : tbe brown colour dis- 

 posed in vein-like ramifications, very distinct towards tbe sides. In front tliere are two conical tentacula, 

 about one eigbth of an incb long, furrowed on the ventral aspect; alltogether marginal, darker coloured at 

 tbe bases froni numerous very minute black dots. About a liue beliind the tentacula there is an oblong 

 blaek spot, divided iuto two equal halves by the mesial fmiddle) line : this spot is pointed in front, trun- 

 cate posteriorly, and is formed by a multitude of dot-like eyes clustered together. The mesial line itself 

 is of a red or blood colour, but does not reach to either extremity. Ventral surface also reddish-brown, 

 but lighter; marked in the middle witb an oblong white space, produced by the retracted proboscis, which 

 is short, white, thick, exsertile, witb a terminal wide and unarmed aperture. Behind the spot produced by 

 it there is another small pore, but whether an anus or sexual orifice is uncertain. — The red line which 

 runs along the centre of tbe back is evidently an alimentary canal ; and the vessels which ramify through 

 tlie body, and on which the colour of the worm depends, appear to arise from it, and are probably in- 

 tended to convey the nutritive fluid directly to the diiferent parts. There is no appearance of any san- 

 guincous System, but the vessels just mentioned are branched in a somewhat dichotomous manner, particu- 

 larly towards the sides ; for they do not reach the margin, neither do they seem to anastomose freely. Their 

 form and disposition are well expressed in the magnified figure. — Planaria cornuta .... inhabits the sea 

 on the coast of Berwicksbire : where it resides in deep water, and is, consequently, only to he found occa- 

 sionally creeping on corallines and shells brougbt up by the lines of fishermen. It progresses by a sliding 

 continuous niotion : and for a worm, its progress is not slow. When in motion, the tentacula are geuerally 

 erect or reflected backwards: it often moves on the side, witb tbe ventral surface half everted; and some- 

 tinies both sides are turned up, so as almost to meet. It dies soon in a vessel, allthough fiUed witb sea- 

 watcr; and, towards its close, will frequently project the proboscis, or even detach it entirely in the struggle. 

 But, though separated, this part retains its irritability for an amazing length of time. On the evening of 

 the day on which a fine specimen was brougbt me, I left it, lively and healtby , in a saucer of sea-water ; 

 but next morning it was found dead, aud the proboscis lying at some distance. Fully twentyfour bours 

 elapsed before I could examine it farther, when , to my astonishment , the proboscis was seen to contract 

 and dilate its aperture witb energj'; yet the body itself had softeued and could not be lifted even on a 

 bair pencil.« 



4) In der Tafelerklärung findet sich die unrichtige Angabe: «des eaux douces de l'Europe.« 



5) »Aug. 2G. 1834. — Mr. Hyxdjl\x dredging to day off Castle Chichester, just withüi the entrance 

 of Belfast bay, and at a depth of from 6 to 10 fathoms, took three specimens on Laminariae. Although 

 the figures of this Planaria in the works cited differ a good deal, I agree with Dr. Joiixston in believing 

 them to represent tbe same species. The Irisb specimens as observed at various times were more round in 

 outline than Dr. Johxstox's figures, aud consequently quite different from those of Mijller in that respect. 

 The network of reddisb »vein-like ramifications« on a cream-coloured ground renders this Planaria viewed 

 as a wbole very beautiful: the multitude of dotlike black eyes on a rieb white ground too looked very 

 elegant from the contrast of the white to the general reddisb hue of the animal." 



6) Hält Planaria cornuta Johxston und Thompson für identisch mit Proceros sanguinolentus Qu.\tref. 

 und für verschieden von Planaria cornuta O. F. Mülle k. 



