PABASOIDTA. I' 1 



of several masses united by a creeping fibre or solid 

 base. [2V.s gelatinous.] Individuals forming one or 

 more systems, each having a common excretory ori- 

 fice. Branchial aperture S-loibed ; a trial without lobes, 

 having a horizontal languet above. Tentacular fila- 

 iin'nts alternately long and short. Thorax and abdomen 

 united continuously. Post-abdomen sub-pedunculated. 

 M. Milne Edwards has divided this genus (or sub- 

 genus*) from Amaroucium on account of its having 

 eight lobes to the branchial aperture, while Amaroucium, 

 and indeed all the other members of the same family 

 yet discovered, have only six. As has been already 

 remarked [Vol. I, p. 17], two of the British species 

 have been referred to tiidni/um. 



1. Parascidia Forbesii Alder. 

 (Plate LIV, figs. 5-7, and PI. LVI, fig. 4.) 



Sidnyum turbinatum FORBES in Brit. Mo]]. I [1848], p. 14, 

 PI. A, f. 2, and PI. B, f. 2; [GossE Man. Marine Zool. II 

 (1856), p. 32, f. 44; WOODWARD Man. Moll. pt. 3 (1856), 

 p. 343; H. & A. ADAMS Gen. Recent Moll. II (1858), 

 pi. cxxxiv, f. 5, 5 a ; NORMAN in Zoologist, XVIII (I860), 

 p. 7247]. 



t Sidnijum turbinatum THOMPSON [in Ann. Nat. Hist. (1) V 

 (1840), p. 264; in Rep. Brit. Assoc. for 1843 (1844), 

 p. 264; and] Nat. Hist, Ireland, IV [1856], p. 361. 



[Non Sidnyum turbinatum SAVIGNY Mem. Anim. sans Vert, 

 pt, 2 (1816).] 



Parascidia Forbesii ALDER in Ann. Nat, Hist. (3) XI (1863), 

 p. 172, [and (MS. sp.) in Ansted's Channel Isl. (1862), 

 p. 219], 



Colony (PI. LIV, figs. 5-7) c^ylindrical and truncated, 

 nearly as broad as high, gelatinous, transparent, orange 

 or amber-coloured, associated in closely-set masses aris- 

 ing from a common incrusting base. Individuals (PL 

 LVI, fig. 4) usually forming a single system of from 

 six to twelve, arranged around a conspicuous central 

 orifice. Branchial aperture with eight palish obtuse 



* Milne Edwards makes both Amaroucium and Parascidia sub-genera of 

 Polyclinum. 



