PLATE XXX. 
Figs. 1-7. Amaroucium irregulare, n. sp. 
Fig. 8. Amaroucium irregulare, var. concinnum, nov. 
Figs. 9-11. Amaroucium 'pallidulum, n. sp. 
Figs. 1 2-1 5. Amaroucium Icevigatum, n. sp. 
Figs. 16, 17. Amaroucium complanatum, n. sp. 
ahd. Abdomen. 
at. 1. Atrial languet. 
br. Branchial aperture. 
en. Endostyle. 
h. m. Horizontal membrane of branchial 
sac. 
i. Intestine. 
l.v. Fine longitudinal vessels of bran- 
chial sac. 
m. CEsophagus. 
p.ahd. Post-abdomen. 
r. Kectum. 
, sg. Stigmata of branchial sac. 
st. Stomach. 
t.e. Test cells. 
fh. Thorax. 
t.m. Test matrix. 
tr. Transverse vessel of branchial 
sac. 
Fig. 1. Colony of Amaroucium irregulare ; natural size. 
Fig. 2. A.ioo\hc,v colonj of Amaroucium irregulare ; natural size. 
Fig. 3. Ascidiozooid of Amaroucium irregulare, seen from left side; magnified 
(S., 1 inch). 
Fig. 4. Part of branchial sac of Amaroucium irregulare ; magnified (S., 1 inch, enlarged). 
Fig. 5. Stomach of Amaroucium irregulare, seen in optical section ; magnified 
(S., 1 inch, enlarged). 
Fig. 6. Alimentary canal of Amaroucium irregulare ; magnified (8., 1 inch, enlarged). 
Fig. 7. Transverse section of abdomen of Amaroucium irregulare, showing folds in 
stomach and rectum ; highly magnified (S., ^ inch). 
Fig. 8. Colony of Amaroucium irregulare, var. concinnum ; natural size. 
Fig. 9. Colony of Amaroucium pallidulum ; natural size. 
Fig. 10. Part of branchial sac of Amaroucium pallidulum ; magnified (S., 1 inch). 
Fig. 11. oi Amaroucium pallidulum ; (S., 1 inch). 
Fig. 12. Colony of Amaroucium Imigatum; natural size. 
Fig. 13. Ascidiozooid of Amaroucium IcBvigatum, seen from right side; magnified 
(S., 1 inch). 
Fig. 14. Part of branchial sac of Amaroucium Imigatum; highly magnified (S., inch). 
Fig. 15. Section of test of Amaroucium Imigatum; highly magnified (S., ^ inch), 
showing arrangement of modified test cells (t.c.). 
Fig. 16. Colony of .4 marowcmm ; .natural size. 
Fig. 17. Part of branchial sac of Amaroucium complanatum; magnified (S., 1 inch, 
enlarged). 
