CYNTHIA CLATJDICANS. 79 



Moll. I [1848], p. 37; [?] THOMPSON Nat. Hist. Ireland, IV 

 [1856], p. 361; [? DICKIE in Eep. Brit. Assoc. for 1857 

 (1858), p. Ill; ANSTED & LATHAM Channel Isl. (1862), 

 p. 219 ; LANSWEEBT in Ann. Soc. Malac. Belg. Ill (1868), 

 Mem. p. 115]. 



Body tuberous, more or less rounded, attached by a 

 broad base. Apertures, branchial terminal, expanded at 

 the margin and prettily striped with rose-colour and 

 yellow ; atrial rather distant, conical, coloured like the 

 branchial. Test tough, rugose, much wrinkled in all 

 directions, and hispid, often encrusted with zoophytes 

 and fragments of shells ; of a rosy brown above, paler 

 below ; inside shining. Mantle orange coloured, 

 strongly muscular. Tentacular filaments doubly pin- 

 nate. Branchial sac with eight folds on the right 

 side and nine on the left. Oral lamina small, smooth. 

 Reproductive organs forming a rounded, slightly 

 lobated mass on each side. 



Diameter about an inch. 



Hub. On oysters, especially in the south (Forbes'). 



SCOTLAND. West Coast (Forbes fy McAndrew). 

 IRKLAND. --[? North-east Coast (Thompson); and 

 Strangford Lough, Down (Dickie, 1857).] 

 CHANNEL ISLANDS. Guernsey (Alder). 

 First record. -[? Thompson,' 1840]. ' 



[The test of this species is represented by fig. 1 on 

 Plate XXX.] 



The mantle is thick, opaque, and muscular ; on the 

 outer surface the various systems of fibres are dis- 



*/ 



tinctly seen, and on the inner they are conspicuously 

 displayed, particularly the transverse fibres which 

 form a beautiful close-set parallel system. The internal 

 pallia! processes are not numerous ; they are large, 

 scattered, and of an irregular form ; the tubes are long. 

 The branchial sac (PL XXXI, fig. 3) has usually 

 eisrht wide folds on the right side and nine on the left : 



O O 



but in one individual examined there were eis^ht on 



o 



both sides. Savigny says that the number varies a 

 little, though there are always more on the left than 



