540 Mr. W. S. Macleay's Anatomical Observations 



The genus Boltenia evidently enjoys some degree of locomo- 

 tion when its flexible pedicle is agitated to and fro by the waves ; 

 and it is not improbable that some points of its construction 

 render this oscillation necessary to its comfortable existence : 

 for we may observe, that one of those Ascididcs which come the 

 nearest to it in structure (the Cynthia mornuS of Savigny) does not 

 attach itself to rocks, but makes shift to float about in the Gulf 

 of Suez by attaching itself to fuci and other submarine plants. 



The second animal which I have to illustrate is sufficiently 

 distinct from the former to allow me to form a new 



Subgenus. CYSTINGIA. 



External Character. Body with a sub-coriaceous test, 



J I: affixed by the summit to a very short pedicle, which is 



in the same line with the two orifices. The branchial 

 orifice quadrifid and lateral, the ana/ irregular and ter- 

 minal ; both being so little prominent as not to alter the 

 form of the body. 



Anatomical Character. Branchial pouch membranaceous, 

 ,. , indistinctly reticulated, and divided into longitudinal 



? •!? '• folds. The tentacida of the branchial orifice compo- 

 site. Intestinal canal lateral. Stomach very large, ex- 



■*,'.\ ,Tuif tending almost the whole length of the body. Ovaries 

 lUtwo, composed of globular ova disposed in free racemes 

 on each side of the body, with the branchial pouch and 

 stomach between them. buiiu. i 



This gentis comes nearer to Boltenia than to any other hitherto 

 described ; and they may prove eventually to be only two sub- 

 genera, 



