614 PEOP. W. A. HEEDMAN S EEVISED 



„ fColonyof a resinous-brown colour. B. mucosum, v. Dr. (Med.) ' 

 I Colony blackish, not sandy B. Pancerii *, D. Valle. (Med.) 



(Colony blackish, sandy on surface. 

 J). Costcs, D. Valle. (Med.) 

 Colony red B. variolosumf, GrEertn. (N.W. E ur.) 



Hbteeoteema, Fiedler, 1889. 



Colony massive, branched, attached. 



Systems placed iu irregularly polygonal areas marked out by 

 grooves. 



Test gelatinous, with no spicules. 



Ascidiozooids with body separated into thorax and abdomen, 

 and having ectodermal processes. Branchial aperture 6-lobed ; 

 atrial not lobed, but with a trifid atrial languet. 



Bi'anchial sac well developed, without internal longitudinal 

 bars, with 8-10 rows of stigmata. 



Dorsal lamina represented by languets. 



Alimentary canal placed behind the branchial sac. Stomach 

 longitudinally, folded. 



Spermatic vesicles numerous, placed in the posterior part of 

 the abdomen. 



This genus, closely allied to Distoma, contains the single 

 species Heterotrema Sarasinorum, FiedL, from Ceylon. 



Ctstodttes, von DrascTie, 1883 (subgen.), Serdm., 1886. 



Colony of irregular form, attached and incrusting, sometimes 

 lobed, and of moderate thickness. 



Ascidiozooids surrounded by capsules formed of calcareous 

 discoid spicules. No ectodermal appendages present. 



Test cartilaginous, containing calcareous disc-shaped spicules 

 which form a capsule round each ascidiozooid. 



Branchial sac small ; about 4 rows of stigmata. 



Abdomen as large as thorax. Stomach smooth. 



The five known species of Cystodytes may be dii?tiDguished as 

 follows : — 



/Ascidiozooids arranged in distinct systems 1 



[Ascidiozooids not distinctly arranged in systems 2 



* B. phimheum, D. Valle (Med.), seems to differ from this only in the size 

 -and proportions of the ascidiozooids. 



t B. ruhnim, Sav., is close to if not identical with this. 



