ASCIDIANS OF GUERNSEY. 



205 



Styela tuberosa {MacGillivray). Guernsey (Alder). Body conical, pale 

 brown, orifices pinkish, test thick, tough and wrinkled. 



S. mamillaris {Gartner). Guernsey (Norman). Body irregular and deeply 

 lobed. 



S. pomaria {Savigny). Guernsey (Hodge and Brady). Gouliot Caves 

 (Norman) . 



S. humilis (?). St. Peter-Port, dredged (Alder). Test thin, sandy, and 



covered with short hairs. 

 S. variabilis (?). Guernsey and Herm (Hodge, Brady and Norman). 

 S. ObSCUra (?). Guernsey, dredged (Jeffreys and Norman). 

 S. fibrillata (?). Guernsey (Norman). 

 S. depressa (?). Guernsey (Norman). 



StyelopsiS gTOSSUlaria {Traastedt). L'Islet, Bordeaux and Castle Cornet 

 (Sharp) . Apertures 4 lobed ; folds of branchial sac reduced to one on 

 or near the dorsal edge of the right ride, the other 7 being quite rudi- 

 mentary. This species may be seen by thousands at L'Islet. Not so 

 plentiful in Alderney. 



Polyearpa glomerata {Aid.) Vazon and Cobo (Sharp). Very common 

 on seaweed washed up ; the rocks at Terres Point are covered with this 

 form. Body sessile. Orifices usually 4 lobed. Branchial sac with four 

 folds or less on each side. In this particular species there are three folds 

 on right side and two on the left. 



Family III.-ASCIDIID^. 



Solitary, fixed ; test gelatinous ; branchial orifice 8 lobed, atrial 6 lobed. 

 Branchial sac not folded ; stigmata straight or curved. Tentacles simple, 

 filiform. 



Corella parallelOgramma {Muller). Guernsey (Ansted). Atrial aperture 

 sessile or on short siphon. Musculature strong on left side. 



Aseidiella scabra [Mailer) . Guernsey (Alder). Dorsal lamina with edge 

 toothed or irregular. Body attached by a large area. Stigmata 12 in a 

 mesh. 



Aseidia mentula {Midler). Castle Cornet (Wright). Bordeaux, Lihou, 

 L'Islet, Alderney (Sharp). This form is common with us and attains a 

 large size, often six inches. The test is thick and red, with bright red 

 orifices. Atrial orifice more than quarter way down the body. A small 

 bivalve, Modiolaria marmorata, is often found in cavities of the test. 



A. robusta {Hancock). Guernsey (Norman). Herm (Br. Tun.) Cobo, in 

 Laminaria washed up (Sharp). Test tough with root-like prolongations. 

 Apertures tubular. 



A. PUbPOtineta {Han.) Guernsey (Norman). Test thin, pellucid and carti- 

 laginous with orifices wide apart. 



A. plana {Han.) Guernsey (Alder). Body smooth, oval, yellow. Test 



thick and cartilaginous. 

 A. AldePi [Han.) Guernsey (Alder). Body conical, yellow. The ends of 



the blood vessels appear on the surface as red bunches of tubes. 

 A. aculeata {Alder). Guernsey (Norman). Bordeaux (Fleure), L'Islet 



and Lihou (Sharp). Test thin, greenish and covered with spiny processes^ 



A. amoena (?). Guernsey (Norman). 



Ciona intestinaliS {Linnaeus). Castle Comet (Wright). Common at Lihou* 

 L'Islet, Bordeaux (Sharp). Alderney (Sharp). Test thin, yellowish 

 green ; siphons highly retractile. Mantle vermilion. This seems to be 

 a favourite home for small animals, both parasitic and otherwise. Three 

 such have come under my notice. 



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