228 RITTER. 
EXPLANATION OF PLATE XII. 
GOODSIRIA DURA. 
The figures were drawn with the aid of a camera lucida and a Leitz microscope, 
excepting when otherwise specified. 
Fic. 1. A colony, natural size, completely covering the surface of a piece of 
seaweed. No buds are present in this colony. Not camera, but as faithful a 
reproduction as possible. 
Fic. 2. A colony, also on a piece of seaweed. The Ascidiozooids much less 
closely crowded than in the preceding. Buds in various stages of development 
are seen, and some of the very young ones are not as near the margin of the 
colony as are some of the older ones. The ampullae of the testicular vessels are 
seen, particularly near the margin of the colony. Not camera, but as exact as 
possible. X 4. 
Fic. 3. Small fragment of a thin colony removed from its substratum and 
examined as a transparent object in clove oil. X 87. 
Fic. 4. Digestive tract with a portion of the branchial sac attached. The 
longitudinal folds of the stomach and the single spiral groove of the intestine are 
seen. X 87. 
Fic. 5. Camera sketch of a section of a colony showing sections of three 
blastozooids in various stages of development. The top of the figure corresponds 
to the top or dorsal surface of the colony ; it is consequently seen that the blood 
vessels of the test, ec.ves., are at a deeper level than are the Ascidiozooids. 
xX 87. 
Fic. 6. Transverse section of an almost fully formed blastozooid, the section 
being well toward the posterior end of the body. X 120. 
Fic. 7. An optical section of two ampullae of the testicular vessels which 
contain a closely packed mass, 4.c., of blood corpuscles. This, together with the 
thick ectodermal wall of these vesicles, give them somewhat the appearance of 
young buds. Drawn from a specimen cleared in clove oil. X 87. 
Fic. 8. A single male “polycarp” attached to the mantle. The short vas 
deferens is here seen. X 120. 
Fic. 9. Optical section of an ascidiozooid with a bud, éd., still attached to it. 
This is the zooid from which the section shown in Figs. 12 and 13 were cut. The 
direction of the section is indicated by the line 4.4.“ The specimen was cleared 
in clove oil. Not camera, but as faithful a representation of the object as 
possible. 
Fic. to. Optical section of a zooid with a young bud, éd. Cleared in clove 
Oil mie toe 
Fic. 11. Section of the earliest stage seen in the formation of a bud. As 
seen, the ectoderm is not yet modified at the point where the bud is forming, the 
bud Ax/age, bd.a., being confined to the parietal wall of the peribranchial sac ; 
by.st.a. are points where stigmata of the present zooid will form. X 210. 
