CLASSIFICATION OF THE ANIMAL KINGDOM. 



Fain. e. BotryUicUe. Botryllus, Didemnum, Ainarou- 



cium. 

 Fam. /. Pyrosomidse. Pyrosoma. 



ORDER II. THALIACEA (BIPHOEA). 

 Fam. a. Salpidse. Salpa. 

 Fam. b. Doliolidse. Doliolum. 



(Milne-Edwards, Observations sur les Ascidies composees de c6tes de la 

 Manche, Mem. Acad. Sci. Paris, 1839 ; Huxley, Upon the Anatomy and 

 Physiology of Salpa and Pyrosoma, Phil. Trans., 1851 ; Hancock, Anatomy 

 and Physiology of the Tunicata, Journ. Linn. Soc., 1868; Heller, Unter- 

 suchungen uber die Tunicaten des Adriatischen und Mittelmeeres, 1874-75 ; 

 Kowalevsky, Entvnckelungsgeschichte der einfachen Ascidien, St Petersburg, 

 1866.) 



Fig. 71. Tunicata. A, Ascidia lata, seen from the right side, of the natural size : b, Bran- 

 chial aperture ; a, Atrial aperture. B, Part of the branchial sac of the same, seen from the 

 inside, magnified, c, Part of the branchial sao of Ascidia virginea ( = Ascidia sordidd), seen 

 from the inside, magnified. (After Herdmau.) 



