DISTOMA V1TREUM. 43 



3. Distoma vitreum M. Sars. 

 (Plate LV, fig. 13, and PI. LVI, fig. 8.) 



Distoina ritrenm M. SAKS in Nyt Mag. f. Naturvid. VI 

 [1851], p. 154, [and in Fo'rh. Vid-Selsk. Christ. 1858 

 (1859), p. 66; ANSTED & LATHAM Channel Isl. (1862), 

 p. 219]. 



Colony greyish white, hyaline, sub-cartilaginous, 

 clavate or fusiform, adhering by a narrow base. 

 liniiciiliinlx white or yellowish, irregularly disposed 

 (PL LV, fig. 13). Brani-hial and olrlal apertures each 

 with six blunt lobes. Abdomen oblong-ovate, united 

 to the thorax by a thickish peduncle. 



Length of mass a quarter to half an inch (6-12 mm.). 



Hab. Adhering to the stem of a zoophyte. 



CHANNEL ISLANDS. Dredged (Norman). 



First record. Alder & Hancock ; coll. Norman. 



A cluster of specimens of different sizes (mostly 

 young) was dredged by Mr. Norman. 



Section 2. With common excretory orifices. 



Genus 21. LEPTOCLINUM Milne Edwards, 1841. 



Leptodinum MILNE EDWARDS Obs. Ascidies comp. [(1841), 

 p. 81, in Mem. Acacl. Sci. List. France, XVIII (1842), 

 p. 297;] FORBES & HANLEY Brit, Moll. I [1848], p. 341 ; 

 G-OSSE Man. Marine Zool. II [1856], p. 33; WOODWARD 

 Man. Moll, pt, 3 (1856), p. 341; H. & A. ADAMS Gen. 

 Recent Moll. II [1858], p. 604. 



Colony incrusting, thin, coriaceous or gelatinous, 

 [polymorphous,] often containing calcareous crystals. 

 Individuals small, set in [many] very indistinct 

 systems, each with a common cloaca and excretory 

 orifice. Brancliial aperture with six rays; a trial plain 

 [but with a long languet]. Abdomen united to the 

 thorax by a short peduncle or sometimes nearly 

 sessile. 



