30 



Order II. BDELLOMORPHA. 



HiRUDiNEA PLANiERiNA, Moquin-Tundon, Monogr, 386. 

 Phyllinid^, Johnston in Ann. SfMag. Nat. Hist. xvi. 438. 

 Bdellomorph^, E. Blanchard in Ann. des Sc. nat. viii. 142 (1847), 

 & xii. 275 (1849). 



Cha?'. Body oblong, flattened, exannulose, smooth and lubricous, 

 acephalous : no eyes : mouth sessile, edentulous and eproboscidean, 

 in the front margin or underneath it, and, usually, with a small suc- 

 torial disc (bothria) on each side : posterior extremity with a large 

 circular disc or with six to eight small pedunculated discs. Intestine 

 with an anal aperture at the posterior extremity of the body. Ner- 

 vous system consisting of two lateral ganglionated cords originating 

 in two cerebral centres placed widely apart. Monrecious or dioe- 

 cious ; the sexual apertures lateral and forwards. Marine parasites 

 of fish and mollusca, infesting the outer surface, and sucking their 

 fluids. The ova are capsulated when excluded, and are attached by 

 a filiform peduncle. The development is unknown. No species is 

 phosphorescent nor iridescent. 



The British genera may be arranged as follows : — 



Suborder I. Cryptoc(ela. 

 The intestine branched, planarian. Monoecious. 



* POLYCOTYLEA. Posterior sucker multipled. 



1. Octobothrium. 



** MONOCOTYLEA. Posterior sucker undivided. 



2. Entobdella. Sucker granulous and armed with two bicuspidate 



hooks. 



3. Capsala. Sucker radiate with a central disc. 



4. Nitchia. Sucker crenulate on the rim with a central disc. 



5. Udonella. Sucker plain, without appendage. 



Suborder II. Rhabdoccela. 



The intestine undivided, cestoid. Dioecious. 

 (J. Malacobdella, 



