AMAROUCIUM. 7 



Colony fleshy [or cartilaginous], massive, lobed and 

 sessile, or turbinate and pedunculated, composed of 

 many systems, more or less circumscribed, and each 

 having a common cloaca and excretory orifice. Indi- 

 viduals [more or less numerous,] elongated. Branchial 

 aperture 6-lobed; atrial without lobes, but with a small 

 process or languet above projecting horizontally. 

 [Branchial sac moderately developed.] Tentacular 

 filament* alternately lono- and short. Thorax, abdomen. 



/ o 



and post-aid omen united continuously (i.e. without 

 peduncles), the post-abdomen more or less elongated. 

 This genus has a great resemblance to Aplidium, 

 from which it chiefly differs in having a general 

 excretory orifice to each system. 



1. Amaroucium proliferum Milne Edwards. 



(PI. LII; PL LIII, figs. 1-3; PL LVI, fig. 2; and 

 figs. 90 and 91 in text.) 



Amaroucium proliferum MILNE EDWARDS Obs. Ascidies 

 comp. [1841], p. 67, [in Mem. Acad. Sci. Inst. France, 

 XVIII (1842), p. 288,] pi. i, ff. 3, 3 , and pi. iii, f. 2; 

 [THOMPSON in Rep. Brit. Assoc. for 1843 (1844), p. 264, 

 and in Ann. Nat. Hist. (1) XIII (1844), p. 434; COCKS 

 in Rep. R. Cornw. Polyt. Soc. for 1849 (1850), p. 74; 

 RUPERT JONES in Todd's Cyclop. Anat. IV, pt. 40 (1850), 

 p. 2022, f. 784 ; GOSSE Nat. Rambles Devon. Coast (1853), 

 p. 322 ; OWEN Comp. Anat. Invert. Anim. ed. 2 (1855), 

 p. 477, f. 180; GOSSE Tenby (1856), p. 29; HUXLEY in 

 Eng-1. Cyclop., Nat. Hist. IV (1856), cols. 1138, 1139, 

 with text-figs.; GEGENBAUER Grundz. verg-1. Anat. (1859), 

 }>. 374, f. 100, and in Arch. f. Anat. 1862, p. 161]. 



[Amauroucium proliferum LOWIG & KOLLIKRR in Ann. Sci. 

 Nat, (3), Zool. V (1846), pp. 221, 222, 226; KROHN in 

 Arch. f. Anat, 1852, p. 313.] 



Amouroncium proliferum FORBES & HANLEY Brit. Moll. I 

 [1848], p. 15; [KROHN in Sci. Mem., Nat. Hist. I, 4 

 (1853), p. 313; NORMAN in Zoologist, XVIII (I860), 

 p. 7247]. 



[Amoercecium proliferum GOSSE Man. Marine Zool. II (1856), 

 p. 33, f. 46, and Year at the Shore (1856), p. 310.] 



