AMAEOLH.'IUM J'AriLLOSVM. 11 



irregular, close-set, ill-defined systems, set round wide 

 common orifices. Branchial <tp< j rfnre with six obtuse 

 lobes. Thorn,?, brownish fawn-colour. Abdomen rather 

 darker. Post-abdomen cylindrical, longish. 



Diameter of mass about an inch (25 mm.) ; height 

 about one-third as much (8 mm.). Length of indi- 

 viduals about half an inch (12 mm.). 



Halt. Shallow water. 



WALKS. Menai Straits, Anglesey 

 First record. Alder, 1803, [coll. 1852]. 



Two specimens only were obtained by dredging. 



4. Amaroucium argus Milne Edwards. 

 (Plate LIV, figs. 1-8 ; and figs. 92 and 93 in text.) 



Amaroucium argus MILNE EDWARDS Obs. Ascidies comp. 



[1841], pp. 21, 74, [in Mem. Acad. Sci. lust. France, 



XVIII (1842), pp. 237, 290, pi. i, f. 4, and pi. iii, f. ] ; 



DESHAYES in Cuvier's Regne Anim., Moll. (dr. 1845), pi. 



cxxx, f. 2 ; RUPERT JONES in Todd's Cyclop. Anat. IV, pt. 



40 (1850), p. 2018, f. 782 ; RYMER JONES Organiz. Anim. 



Kh) K d. ed. 2 (1855), p. 486, and eel. 3 (1861), p. 484]. 

 Amouroucium argus FORBES & HANLEY Brit. Moll. I [1848], 



p. 16, pi. A, f. 4; [COCKS in Rep. R. Cornw. Polvt. Soc. 



for 1849 (1850), p. 74; H. & A. ADAMS Gen. "Recent 



Moll. II (1856), pi. cxxxv, ff. ], In; FORBES & GODWIN- 



AUSTEN Nat. Hist. Enrop. Seas (1859), p. 158]. 

 \_Amouroecium argus MeAxDREW & BARRATT in Ann. Nat. 



Hist, (2) XVII (1856), p. 385.] 

 [AmoroBcium argus WOODWARD Man. Moll. pt. 3 (1856), 



p. 343, pi. xxiv, f. 17.] 

 [Amaurcecium orgnx BRONN Thier-Reichs, III (1861), pp. 



136, 180, pi. xiv, f. 4.] 

 [Amoroucium argus ANSTED & LATHAM Channel Isl. (1862), 



p. 219.] 



Colony massive or sub-cylindrical, and sessile (PI. 

 LIV, fig. 2), rarely pedunculate (PI. LIV, fig. 3), of a 

 yellowish-orange colour inclining to olive near the base, 

 more distinctly orange above, and pale spotted with 

 red at the summit. Individuals (fig. 93) rising a little 

 above the surface, arranged irregularly in one or more 



