Phallusia. MOLLUSCA. TUNICATA. 469 



tubular, with divided margins, and intermediate scarlet spots ; the anal ori- 

 fice is a little below, with six spots, the upper branchial one with eight—It 

 is not uncommon in the Zetland seas. 



Gen. CXLVIII. PHALLUSIA.— Branchial sac extending 

 beyond the viscera into a pouch of the tunic ; stomach rest- 

 ing on the viscera. 



590. P. mentula. — Oval, compressed, hairy, the inner tunic 

 red. 



Ascidia ment. Mull. Zool. Don. t. viii. f. 1-4. Mont. Test. Brit. 542. 

 Stewart's Elem. i. 391. — Adheres to rocks. 



Length 2 or 3 inches ; brown ; rough, often with adhering fragments of 

 corals and shells ; apertures distant, reddish. 



591. P. rustica. — Subcylindrical, rough, the apertures ap- 

 proximate. 



Ascidia rust. Linn. Syst. i. 1087. Mull. Zool. Dan. t. xv. f. 1-5. Steic 

 art's El. i. 391 — Adheres to stones, shells, and fuci. 



liCngth about two inches ; outer tunic yellowish ; rough and obtuse when 

 old, red and hemispherical when young, whitish inside ; inner tunic reddish. 



Gen. CXLIX. POLYZONA.— Body polymorphous, with 

 many systems arranged subcircularly. 



592. P. variolosa. — " Crustaceous and leathery, with scat- 

 tered papillae, and two subdentated mouths." 



Alcyonium ascidioides, Stewart's El. ii. 432. Tiirt. Brit. Fauna, 208. 



Adhering to the fucus palmatus on the coast of Cornwall. 



This species, which was first observed by Gaertner, and communicated by 

 him to Pallas (Spicil. Zool. fasc. x. t. iv. f. 7-) is thus described by its disco- 

 verer : " Crusta, coriacea, tenax, crassiuscula, subtus plana, supra verrucis 

 crebris, variaeque magnitudinis conspersa, coloris vel dilute rubicundi vel ex 

 croceo albicantis. Verrucae seu tubercula maximam partem ovalia et ex 

 croceo rubra sunt : singulum autem duplici perfoi'atum est orificio minimo 

 coccineo, quod turgidulus margo ejusdem coloris atque sex distinctus radiis, 

 quasi in tot discessus fuerit dentes, cingit." — Sav. Mem. 38. 



Gen. CL. SYDNEUM.— Body inversely conical ; anal orilice 

 simple and tubular. 



593. S. turbinatum. — Pale red, gelatinous, and transparent. 



Sav. Mem. 238 On rocks. 



Length about half an inch above the common base, which spreads on the 

 rocks ; narrow below, and gradually becoming thicker towards the top, the 

 summit of which is slightly concave ; mouths prominent, freckled with yel- 

 low, with short blunt conical tentacula ; stomach surrounded with glands ; 



