L TURBELLARIA. 



I. PLANARIEA. 



Sangsues-limaces, Reaumur, Hist. Insect, vi. pref. Iviii. 

 Planari A, Lam. An. s. Vert. iii. 1 7G' Schweig. Handb. 593. Daly ell, 



Pow. Great, ii. 96 & 125. 

 Planariad^e, Flem. Phil. Zool. ii. 604. 

 Planari^, Blainville in Diet, des Sc. nat. Ivii. 577 ; Ann. 4* Mag. 



Nat. Hist. xvi. 227. 

 Planarin^e, Johnston in Ann. ^ Mag. Nat. Hist. xvi. 436. 

 Anevormi (— ), E. Blanchard in Ann. des Sc. nat. vii. 105, 106 



(1847); and viii. 119, 141 (1847). 

 Aporocephal^, E. Blanchard in Ann. des Sc. nat. viii. 143 (1847). 

 Planariea, Oersted, Entw. Plattw. 41. Diesing ( X ), Syst. Helm. 



i. 184. Ray Soc. Rep. Zool. 1847, 516. 

 Aprocta, Schultze, Naturg. Turbell. 3. 



Fam. I. PLANOCERID-ffi. 



Cryptoccela, Oersted, Entw. Plattw. 44. f. 2. p. 12. Rep. Ray Soc. 

 Zool. 1847, 517. 

 Obs. The body is thin, flat, and laterally expanded, with a plain 

 margin. The eyes, when present, are clustered. The oral aperture 

 is usually closed and becomes almost indistinguishable, but the posi- 

 tion of it, and of the proboscis, is marked by an oblong spot near the 

 middle of the ventral surface. This is always paler than the dorsal, 

 which is commonly beautifully coloured. The motion is slow. The 

 food is soft, either the juices of avertebrate animals or the paren- 

 chyma of decaying algae. All are marine, and propagate, probably, 

 by naked ciliated ova, undergoing no metamorphosis. In decay, the 

 body is diffluent ; and decomposition has far advanced before life is 

 extinguished. 



1. LE^TOVLA-NA, Mrenberg, 1831*. 



Leptoplana, Oersted, Entw. Plattw. 48, Diesing, Syst. Helm. i. 194. 

 Prosthiostomum, Quatrefages in Ann. des Sc. nat. iv. 133 (1845). 

 Polycelis, Quatrefages in ibid. 132. 



Char. Body flat, entire, with a smooth dorsum : mouth subcen- 

 tral : eyes in two or four clusters : genital pore behind the mouth. 



* When, as in this example, the name of the founder of the genus immediately 

 follows the generic name, the date of the latter rests on the authority of Agassiz's 

 Nomenclator Zoologicus. In these instances, I have not had an opportunity of 

 consulting the original authority. 



