BRITISH MARINE TURBELLARIA. " 615 



b. With spermotheca . . Genua Monoporus. 



Species: — M. rubropunctatus (eyes without lenses, 

 composed of red pigment-masses placed in the 

 epidermis). 



2. With two genital pores, the female pore in front of the 

 male ..... Family Aphanostoinidae. 



a. Spermotheca with soft, non-chitinous mouth- 



piece . . . Genus Aphangstoma. 



Species: — A. diversicolor (central part of the ante- 

 rior end violet, extremities yellow). A. elegans 

 (centre of the body with a lobate green spot). 



b. Spermotheca with chitinous mouth-piece 



Genus Convoluta. 

 Species: — C. saliens (with alternate longitudinal 

 rows of cilia and rhabdites). C. paradoxa (with 

 two eyes and " yellow cells " in the parenchyma). 

 C. flavibacillum (dorsal surface very convex, no 

 "yellow cells," sides of the body only slightly 

 flexed ventrally). 



Section B. — Rhabdoccela.^ 



3. With sexual and asexual reproduction. Female accessory 

 organs absent .... Family MicrostomidaB. 



a. Sexes separate. Head with a pair of lateral grooves. 



A pre-oesophageal caecum present 



Genus Microstoma. 

 Species : — M. grmnlandicum (eyes absent, a red spot 

 usually present anteriorly). 



b. Hermaphrodite. Proboscis present. A posterior 



and sometimes lateral bundles of setae 



Genus Alaurina. 

 Species: — A. Claparedii (proboscis with numerous 

 papillae, and a pair of ciliary tufts at its base; 

 posterior bundle of setae only) . 



4. With one or two genital apertures. Male accessory 



1 See p. 448. 



