3^6 MANUAL OF THE MOLLUSCA. ; 



ratory function is performed by the entire pallia] cavity. The muscles of the 

 Salpae consist of single layers of tranversely striped fibre. 



DoLiOLUM, Quoy and Gaimard. " , 



Hf^m. Dim'mntive o{ doliiim a cask. .Sj//^. ? Auchinaea, Esch. 



Type, D. denticulatura, PI. 24, fig. 23. I 



Body transparent, cask-shaped, open at the ends, 2—10 lines in length; 

 oral extremity a little prominent, Avith about 12 rounded denticulations ; 

 posterior end fringed ; muscular bands 6, equidistant, besides the sphincters 

 of the orifices ; branchiae consisting of two bands stretched across the interior, 

 one above {e-pi) and one below {hyi)oplianjngeaT), connected by transverse 

 bars with one another and the parietes ;' mouth on the dorsal side, in front of i 

 the fourth band ; heart above and in front of the mouth. {Huxley.) 



Bistr. 2 sp. Amboiua, Yanicoro, N. Zealand. 



Appendicllaeia, Chamisso. \ 



Efym. Appendlcidvs, a small appendage. 



Syn. Yexillaria, :Mu11. 1846. Oikopleura, Mertens, 1831. i 

 Tyj^e, A. flabellum, PI. 24, fig. 24. j 

 Body ovoid, i — \ inch long, with a long curved tail or swimming- ; 

 organ ; smaller end perforated, leading into a large cavity lined by a sinus- | 

 system ; gill represented by the ciliated pharynx, which communicates with : 

 the exterior by two funnel-shaped canals opening on the haemal sm-face beside i 

 the rectum ; oesophagus short, slightly curved, leading into a wide stomach ; ■ i 

 intestine turned forwards, ending on dorsal side in front of appendage; \ 

 heart between lobes of the stomach ; tail lanceolate, horizontally compressed. 

 All the examples hitherto observed have been males. {Huxley.) ' 

 These minute creatures appear to be the lowest forms of the Tunicata ; i 

 typifying in their adult age the larval state of the higher ascidians. { 

 Disir. Behring's Straits, N. Brit. Tenby, Cape, New Guinea, S. Pacific. I 

 Prof. Forbes relates that " when cruising oft' the north coast of Scotland 

 in 1845, with Jlr, Mc Andrew, their attention was attracted by the appear- 

 ance of cloudy patches of red colom'ing matter in the watqr, and on procuring ' 

 some and submitting it to microscopic examination, it was found to consist ) 

 entirely of the curious and anomalous creatures called AppejidiculartcE'^* \ 



'* The most complete and accurate liistor}' of the class Tunicata is contained in the 

 Article Tunicata of Todd's Cyclopcedia of Anatomy, \>y Mr. T. Rupert Jones, 



