TUEBEIJ^ARIA. 



Familia 



Monogonopora, Stimpson. Apertura genitalis miiea. 



PLANAEIADAE, Stimpson. Corpus oblontjum, plamim, saepe lobis au- 

 riculaeforniihus, rciriter tentaculis. Os oentrale I. p)osfici(,m. Oesophagus 

 integer. Apertura genitalis ad posteriora oris sita. 



Planaria Miill . Caput interchim. indistincte discretum, trigonum, 

 tentaculis nullis; oculis duobus. Os sicbcentrale ; cyliudriewn . (Tubi ei- 

 barii rami indivisi, Oersted); penis in communi apertwm genitalis 

 vestibulo. 



PI. torva, auctorum. Corpus antiee obtuse trilobimi, postice acu- 

 minatum, supra einereum I. nigrum; subtus albidum. Lg 8 — 10; lat. 

 2,0 m, m. 



Synon. Fasciola torva, 0. F. Miiller i. ii. 62; 

 Planaria torva. Oersted 54; Diesing i. 205; G-erstfeldt 262; G. John- 

 ston 1 1 . 

 Planaria fusca, Linne S. Nat xni. 3090; Diesing I- 204. ^ 



Habit. Et aqvise dulcis et subsalinje incola. — Abo, 

 Helsingfors, Nadendal, Reso, Helsinge, Mantsala. 



Diesing attributes to Planaria torva: ocellus singulus! — 

 In the »Zeitschrift fiir wissens. Zoologie», Bd XI p. 89, O. 

 Schmidt gives a description of three species into wihch, accor- 

 ding to his opinion, PI. torva, auctorum, is to be divided. 

 The characters he has got from the shape of the body, espe- 

 cially the fore-part of it, from the position of the eyes, from 

 the colour of the body and the structure of the generative or- 

 gans. I recollect having sometimes seen specimens that, as for 

 the shape and the colour, have corresponded to his PI. lugubris; 

 but as I have not since got similar specimens for examining, 

 it may be suificient to have mentioned it by the by ! — Gerst- 

 feldt, o. c. p. 262 & 263, describes a new species, PI. guttata. 

 However it seems to me that the characters given by him are 

 rather unessential and fall within the limits of individual varia- 

 bility, as for an example, the smooth in spirit not curled (gekrau- 

 selt) margins of the body, the running together of the white 

 spots surrounding the eyes, the flat, leaf-shaped body, the light 

 linear-oblong mesial spot and the two lateral series of 4, 5 or 

 6 rounded, light spots. — Planaria, as Johnston tells, has the 

 tail rounded; which may depend on some misstake; as I, not 

 to reckon the extraordinary capacity of those animals in mo- 

 ving to change the shape of the body, always have had occa- 

 sion to see the tail of PI. lactea, Johnst, to be very acumina- 

 ted, the animal being in rest. With regard to the shape of the 

 tail PI. torva is intermediary between Dendrocoelum lacteum 

 and Polycelis nigra. 



Deiidrocoelum, Oersted. Caput lobis atiHculaefortnibus ; tentaeuli 

 nulli; os oesopliagusque ut Planariarmn (tubi cdbarii rami arbmcidi- 

 fonnes. Oersted); penis retortaeformis, inermis, longe Kaginatus, 



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