18 



BRITISH TUNICATA. 



duals, and these in Amaroucium fallax are stated to be 

 divided into six short segments. The general body, 

 however, in this species is smaller and less massive 

 than in Aplidium fie us, and of a different colour. 

 Forbes' figure in ' British Mollusca ' (PL A, f . 1) does 

 not appear to represent the same species as Johnston's. 

 His figure in PL B is taken from Savigny's Aplidium 

 lobatum. The presence of a languet in Dr. Johnston's 



FIG. 96. Amaroucium fallax. A, a group, natural size. B, a single 

 individual, x about 16. (After Johnston, loc. cit.) a, branchial 

 aperture ; b, branchial sac ; c, oesophagus ; d, stomach ; e, intes- 

 tine ; /, atrial aperture ; g, ovary. 



figure leads to the conclusion that this species is an 

 Amaroucium. 



Genus 16. PAKASCIDIA Milne Edwards, 1845? 



Parascidia MILNE EDWARDS in [Disciples' ed.] Cuvier's 

 Regne Anim., [Moll, by Deshayes (dr. 1845), Descr. pi. 

 cxxx, fig. 3] . 



Colony cylindrical or turbinate, generally consisting 



