590 ASCIDIIDiE. 



circle of tentacular filaments, anal orifice six-lobed ; bran- 

 chial sac not plicated, the meshes papillated. 



Syn. Ascidia, Linnaeus. Phallusia, Ciona, Pirena, Sa- 

 vigny. Alina, Risso. ? Mammaria, 0. F. Midler. 



Ex. A. mentula, O. F. Midler, pi. 133, fig. 1. 



The Ascidia are frequently found attached to the under 

 surface of rough stones on the shore at low-water in various 

 parts of the world. " They are variously and often splen- 

 didly coloured, hut otherwise unattractive or even repulsive 

 in aspect. Numbers of them are often found clustering 

 among tangles, like bunches of some strange semi-tran- 

 sparent fruit." (Forbes.) 



Species of Ascidium. 



amphora, Agass. orbiculare, Midler. 



arachnoideum, Forbes. papilla, Daly ell. 



aspersurn, Midler. paralellogramma, Midler. 



callosum, Stimp. prunum, Midler. 



caninum, Midler. psammopborum, Agass. 



carueum, Agass. rugosum, Agass. 



concbilega, Midler. rusticum, Dalyell. 



echiuatum, Linn. scabrum, Midler. 



geometricum, Stimp. tenellum, Stimp. 



hirsutum, Agass. turcica, Sav. 



intestinale, Linn. venosum, Midler. 



mentula, Midler. villosum, Dalyell. 



monacbus, Cuv. violacea, Goidd. 



rnonstrans, Goidd. virgineum, Midler. 



ocellatum, Agass. vitreum, Van Ben. 



Genus MOLGULA, Forbes. 



Body more or less globular, attached or free ; test mem- 

 branous, usually invested with extraneous matter ; orifices 



