PLATE III. 



at. Atrial aperture. 



at.l. Atrial loljes. 



br. Branchial ajierture. 



br.l. Brancliial lobes. 



dJ. Dorsal tubercle. 



en. Endostyle. 



i. Intestine. 



Doliolum. 



nt'-Hi'. Muscle bands. 



n-rj. Nerve ganglion. 



ce. (Esophagus. 



p.p. Peripharyngeal bands. 



a. Stolon. 



sg. Stigmata. 



St. Stomach. 



Figs. 1-6. Diagrams showing the position of the endostyle and the extent of the 

 branchial sac in various species of Doliolum. 1-8. Muscle l)ands ; 

 en. Endostyle ; sg. Stigmata of branchial sac. 



Fig. 1. Doliolum krohni, n. sp. 



Fig. 2. Doliolum gegenbauri, Uljanin. 



Fig. 3. Doliolum tritonis, Herdman. 



Fig. 4. Doliolum challengeri, n. sp. 



Fig. 5. Doliolum ehrenbergi, Krohn. 



Fig. 6. Doliolum affine, n. sp. 



Fio-. 7. Alimentary canal of specimen of Doliolum ehrenbergi obtained in the North 

 Atlantic, May 12, 1876 (S. 1). 



Fig. 8. Specimen oi Doliolum affine obtained in the South Pacific, October 19, 1875, 

 from dorsal surface (S. 1). 



Fig. 9. Blastozooid of Doliolum sp., obtained in Bass Strait, April 2, 1874, from 

 dorsal surface (S. 1). 



