632 PEOT". w. A. heedman's ebvised 



Eucoelium lospitiolum, Sav., f rom the Eed Sea and tlie Mediter- 

 ranean ; but the following have been placed under Eucoelium : — 



E. ravum, Grube, (Med.) 



E. parasiticum, Giard. (N.W. Eur.) [A Leptoclinum.'] 



E. croceum, Eisso. (Med.) 



E. flaviclum, Risso. (Med.) 



E. subgelatiiiosum, D. Oh. (Med.) 



E. roseum, D. Oh. (Med.) 



Family V. DIPLOSOMIDtE, Giard, 1871. 



Colony forming a thin incrusting layer, rarely thickened, never 

 pedunculated. 



Systems irregular, usually inconspicuous. Common cloacal 

 apertures usually visible. 



Ascidiozooids divided into two distinct regions, thorax and 

 abdomen. 



Test soft and gelatinous, usually transparent, sometimes pig- 

 mented, rarely containing calcareous spicules. Yascular ecto- 

 dermal appendages provided with muscle fibres penetrating the 

 test. 



Branchial sae large, with four rows of stigmata. 



Dorsal lamina represented by large languets. 



Alimentary canal extending behind the branchial sac. Stomach 

 smooth-walled. 



Gonads behind the intestinal loop or on its right side. Testis 

 forming more than one mass. Vas deferens not coiled spirally. 



Gemmation pyloric. Larva gemmiparous. 



There are two distinct genera : — • 



f With calcareous spicules in the test Diplosomoides. 



\ With no spicules in the test , Diplosoma. 



Diplosomoides *, Herdman, 1886. 



Colony usually thin and incrusting, sometimes only slightly 

 attached. 



Test gelatinous, sometimes firm externally, more or less opaque 

 and of a whitish colour. Calcareous stellate spicules present in 

 the superficial layer. Otherwise as Diplosoma. 



* Lahille has recently used this genus in a new and totally distinct sense, 

 and therefore the species he refers to Diplosomoides are not related to my 

 species. 



