PXATE XLII. 
Figs. 1-4. Diplosoma macdonaldi, n. sp. 
Figs. 5-16. Diplosomoides molle, n, sp. 
hi. Bladder cell. 
hr. Branchial aperture. 
hr.s., hr. s'. Branchial sac. 
d. 1. Dorsal lamina. 
d.t. Dorsal tubercle. 
en. Endostyle. 
i., i'. Intestine. 
1. Languet. 
l.v. Fine longitudinal vessels of bran- 
chial sac. 
m.f. Muscle fibres. 
a. (Esophagus. 
'p.'p. Peripharyngeal band. 
sg. Stigmata of branchial sac. 
st, St'. Stomach. 
t. c. Test cells. 
tn, trl. Tentacles. 
tr. Transverse vessel of branchial sac. 
v.ap. Vascular appendage. 
Fig. 1. Colony of Diplosoma macdonaldi, attached to a Hy droid Zoophyte along with 
a Polyzoon and a Sponge ; natural size. 
Fig. 2. Part of colony of Diplosoma macdonaldi, showing Ascidiozooids ; magnified 
(S., 1 inch). 
Fig. 3. Part of test of Diplosoma macdonaldi; highly magnified (S., \ inch). 
Fig. 4. Part of branchial sac of Diplosoma macdonaldi; highly magnified (S., ^ inch). 
Fig. 5. Colony of Diplosomoides molle ; natural size. 
Fig. 6. Part of colony of Diplosomoides molle, showing Ascidiozooids ; magnified 
(S., 1 inch, reduced). 
Fig. 7. Ascidiozooid of Diplosomoides molle, seen from right side, showing gemmation 
(br.s', st', i')\ magnified (S., 1 inch). 
Fig. 8. Another Ascidiozooid of Diplosomides molle, seen from right side, showing 
gemmation ; magnified (S., 1 inch). 
Fig. 9. Ascidiozooid of Diplosomoides molle, seen from left side ; magnified (S., 1 inch). 
Fig. 10. Vascular appendage of Diplosomoides molle; highly magnified (S., ^,mch). 
Fig. 11. Optical section of bulb on vascular appendage; highly magnified (S., \ inch). 
Fig. 12. Spicules from test of Diplosomoides molle; highly magnified (S., \ inch). 
Fig. 13. Anterior end of Ascidiozooid seen from branchial sac, showing tentacles, &c. ; 
highly magnified (S., ^ inch). 
Fig. 14. Part of branchial sac of Diplosomoides molle; highly magnified (S., ^ inch). 
Fig. 15. Small part of dorsal edge of branchial sac of a young Ascidiozooid of Diploso- 
moides molle, showing languets ; highly magnified (S., \ inch). 
Fig. 16. Dorsal languets of an adult Ascidiozooid of Diplosomoides molle; highly 
magnified (S., ^ inch). 
