Fig. 46. 



FAMILY XIII. ESCHARID^. 



35. Flustra,* Linnaeus. 

 Character. Polj/pidom plant-like, membranaceous, Jlexile, 

 frondose or crustaceous, formed of cells arranged quincuncially in 

 several series and in one or two layers : cells in juxtaposition, 

 more or less quadrangular, fat, with a distinct border ; the 

 aperture transverse, semilunar, valvular, subtermijial.'f — Poly- 

 pes ascidian. 



* Foliaceous, with cells on both sides. 

 1. F. FOLiACEA, cells narrow at the proximal and arched at 

 the distal extremity., with scattered marginal denticles. 



Plate xxxv. Fig-. 1, 2. 

 Fucus marinus scruposus albidus telara sericeam textura sua semulans, Mor- 

 ris. Hist. Plant, iii. 646, tab. 8, fig. 16. (bona.) Fucus telam lineam 



sericeamve textura sua aemulans, Rail, Syn. 42, no. 9. Jussieiiin Mem. 

 Acad. Roy. des. Sc. 1742, 298, pi. 10, fig. 3 Broad-leaved Horn- 

 wrack, Ellis, Corall. 70, no. 2. pi. 29, fig. a, A. B, b Curious sea- 

 weed, Hoohe, Microg. 140, pi. 9, fig. 2 ; and pi. 14, fig. 1. Eschara 



foliacea, Lin. Syst. edit. 10, 804. Pall. Blench. 52 Flustra folia- 



cea, Lin. Syst. 1300. Mull. Zool. Dan. prod. 253. Fabric. Faun. 

 Groenl. 436. Ellis and Soland. Zooph. 12, pi. 2, fig. 8. Berk. Syn. i. 

 214. Turt. Gmel. iv. 663. Wern. Mem. i. 563. Turt. Brit. Faun. 



• From the Saxon Flustrian, to weave : hence Flustra applied by Linnieus 

 to these sea-mats. 



f " The aperture of the cells is formed by a simicircular lid, convex exter- 

 nally and concave internally, which folds down when the polypus is about to 

 advance from the cell. The opening of this lid in the F. truncata, where it is 

 very long, appears through the microscope like the opening of a snake's jaws, 

 and the organs by which this motion is efl!ected are not perceptible. The lid 

 of the cells opens and shuts in Flustric, without the slightest perceptible 

 synchronous motion of the Polypi." Grant in Edin. New Phil. Journ, iii. 339. 



