TUNTCATA. 337 



FAMILY 1, AsciDiADAE. Simple Ascidiaus. 



/^ nm a I shn\}\e, fixed; solitary or gregarious ; oviparous; sexes united; 

 branchial sac simple or disposed in (8 — 18) deep and regular folds. 



The simple ascidians were called tethya and well described in Aristotle's 

 History of Animals.* Many of them are esteemed as articles of food iu Bi-azil, 

 China and the Mediterranean ; at Cette they are regularly taken to market ; 

 and Cynthia microcosmiis^ furnishes a delicate morsel, much sought after. 



AsciDiUM, Baster 1764. Sea-squirt. 



'Etym. Diminutive oiaskos, a skin-bottle. 



Syn. Alina, Risso : Phallusia, Pirena, Ciona, Savigny. 



Ex. A monachus, Cuv. fig. 224, Tenby. 



Body sessile, covered ^^ith a coriaceous or gelatinous tunic ; branchial 

 orifice 8-lobed, furnished inside with a circle of simple tentacular filaments ; 

 anal 6-lobed ; branchial sac not plaited, its meshes papillated. 



The ascidia vary in length from 1 inch to 5 or 6 inches. The test is 

 pale and semitransparent, the inner tunic orange or crimson, or sometimes 

 marbled with crimson and white ; the ocelli arc red, or yellow with a central 

 red spot. The surface of A. echinatum is studded with conical papillae, 

 each with 4 — 7 radiating bristles. The ascidia range from low-water to 

 20 fathoms, attached to rocks, shells, and fuci. 



Blstr. Greenland, Spitzbergen, U. States, Eui'ope, (especially in tlie 

 north), Brit. 19 s]). Medit. New Zealand. 



MoLGULA, Forbes. 



Etym. Diminutive of molgos, a bag of skin. 



Ex, M. arenosa, A. and H. (not M. tubulosa Ratlike), PI. 24, fig. 1. 



Body more or less globular, attached or free ; test membranous, usually 

 invested with extraneous matter ; oritices on very contractile, naked tubes ; 

 oral opening 6-lobed, anal 4-lobed. 



M. arenosa is found in the muddy lochs and bays of the west of Scot- 

 land ; it comes up in the dredge like a little ball of sand. At Tenby it occurs 

 between tide-marks, and in the laminarian zone. 



M. oculata was dredged, adhering to a scallop, in 25 fathoms, off 

 Plymouth ; its orifices are like dark eyes in a spectacle-formed frame. {Forbes). 



Bistr. 3 sp. Denmark, Brit. 



• L'nnaeus used the name Tethyum for the Tunicaries in the earlier editions of 

 his " Systema Naturae," and recognising their resemblence to the bivalves, called the 

 animal of the latter " a tethys." Afterwards he adopted Easter's name Ascidium, and 

 used Tethys for a nudibranche; Tethya (Lam.) is now e ployed lor a genus of 

 globular sponges. 



t So called from the little world of parasites that ofter grow upon it. 



