MALACOZOA. APODA. HETEROBRANCHIATA. 309 



to stones, shells, algee, or otlier bodies, some however 

 being free. 



SYNOPSIS OF THE ABERDEEXSHIRE SPECIES. 

 ORDER I.— APODA HETEROBRANCHIATA. 



Brauchise adherent internally to the tube extending 

 from the upper part of the body to the mouth. 

 ; 'Erepos-, different or diversiform ; Bpdyxt-a, gills. Blain- 

 viUe. 



Family I. — Ascidiixa. 



Body enveloped in a thick skin, fixed in a reversed 

 position, and terminated above by two orifices, placed 

 near each other. Name from the genus Ascidia. 



Genus 1. Cyxtiiia. — External sac sessile, fixed by a 

 broad base, coriaceous, with two quadriradiate apertures. 

 Cynthia, a name of Diana. Saviguy. 



1. Cynthia tvberosa. — Subovate or hemispherical, 

 cartilaginous, with irregular, rough prominences, greyish- 

 white. Tuherosus, with prominences. 



Genus 2. Ascidia. — External sac oval, conical, or cy- 

 lindrical, fixed by a broad base, with the upper aperture 

 octoradiate, the lower sex-radiate. 'Ao-/ct6tW, *' a small 

 leathern bottle." Linnaeus. 



1. Ascidia Primuni. — Subovate, compressed, or di- 

 versiform, softish, rugose, transparent, hyaline tinged 

 with blue ; the ax^ertures with reddish rays. Frthiuni, 

 a prune or plum. 



2. Ascidia opalina. — Subovate, or somewhat square, 

 compressed, very dense, cartilaghious, opalo-hyaline or 

 bluish-white; the apertures not coloured. Oj^alinuSj 

 Hke opal. 



3. Ascidia intestinal is. — Subovate, when extended 

 subcyhudi'ical, softish, smooth, transparent, hyaline. 



