ASCIDIANS OF GUERNSEY. 



207 



B. Leachii (Sav.) Pleinmont Point, Alderney (Sharp). Purple with yellow 

 and white marks. 



B. FUbrum {M.-Edw.) Ha velet Bay (Sharp). Yellow to red. 4 tentacles. 

 B. albicans (M.- Edw.) Lihou (Sharp). Pure white. 

 B. pusilla {Alder). Guernsey (Ansted). 

 B. sparsa {Alder). Guernsey (Ansted). 



Family II.— DISTOMIDiE (Giard). 



Ascidiozooids divided into two regions, thorax and abdomen. Colony, 

 rounded and massive, rarely incrusting. Systems irregular, inconspicuous or 

 absent. Testes numerous, vas deferens not spirally coiled. 

 Distoma rubrum {Sav.) Bordeaux, Castle Cornet, L'Islet (Sharp). Colony 



red. More than three rows of stigmata. A red planarian worm may 



sometimes be seen gliding over this species, thus affording a splendid 



example of protective coloration. It has not yet been identified. 

 D. Vitreum {Sav.) Wall of stomach grooved longitudinally ; 12 of stigmata. 



Guernsey (Ansted). Cobo (Sharp). 



Prof. Herdman remarks " B. vitreum is either the D. crxsUdllunm 



(Ren.), or closely related to it." Also that D. rubrum is either the B. 



variolosum of Gsertner or close to it. 



Family III — POLYCLINIDjE. 



Ascidiozooids divided into three distinct regions. Branchial aperture 6 

 to 8 lobed ; atrial often with atrial languet. Colony usually massive ; some- 

 times incrusting, lobed or even pedunculated. Systems of various shapes. 

 Common cloacal aperture, usually inconspicuous. Branchial sac usually 

 small ; stigmata usually small. 



Aurantium aurantium {M.-Edw.) "This genus or sub-genus seems to 

 differ from Polyclinum merely in having the systems compound " (Herd- 

 man]. Castle Cornet, Albert Harbour, Terres Point (Sharp). 



Polyclinum fieus (Sav.) Cobo (Sharp). Post abdomen attached to poste- 

 rior end of abdomen. Not gelatinous ; colonr olive green. This species 

 exudes a most unpleasant odour when broken. 



Aplidium fallax (Johns). Lihou, L'Islet and Bordeaux (Sharp). Atrial 

 languet not bifurcated. Ten grooves on stomach. Surface studded with 

 black and white specks. 



A. ZOSterieola (Giard). L'Islet, Bordeaux, Lihou (Sharp). Stomach 

 grooves 10 or more ; colony not sandy ; branchial sac not pigmented. 

 Forms small rounded colonies on Zostera. 



A. gelatinosum (?). Albert Harbour (Sharp). This forms white, flocculent 

 masses attached to Zostera. 



Amaroueium Nordmanni (M.-Edw.) Guernsey (Ansted). Colony mas- 

 sive ; branchial orifice 6 lobed ; systems simple, regular, and with few 

 Ascidiozooids. Colour rose. 



A. albicans (M.-Edw.) Atrial languet tri-lobed. Forms white nodular 

 masses. Lihou, Cobo, Vazon (Sharp). 



A. proliferum (M.-Edw.) Guernsey (Ansted). Lihou (Sharp). Orange- 

 red fleshy masses, generally lobed, occasionally incrusting. 



Morehellium argUS (M.-Edw.) Common in many places round the coast 

 (Sharp). Alderney (Sharp). Colony pedunculated, systems inconspi- 

 cuous. Ascidiozooids not distinctly marked into regions. Branchial 

 orifice 6 lobed. Test gelatinous ; branchial sac large and well developed. 

 Dark orange or red in colour. 



Parascidia Forbesi (Alder). Guernsey (Ansted). Ascidiozooids divided 

 into thorax, abdomen and post abdomen. Branchial orifice 8 lobed. 



