W. G. Van Nan ie — Bermuda Ascidians. 37 7 



the common cloacal chamber into which it discharges. It is usually 

 back a considerable distance from the anterior end. 



The stomach has about eight or ten longitudinal folds and a large 

 ccecum on the side toward the intestine. With this the duct from 

 the glandular organ about the intestine communicates. The tubes 

 of this organ have large dilated extremities. 



The male reproductive organs consist of a large many-lobed testis 

 on each side, near the posterior end of the branchial sac; just anterior 

 to them the ovai'ies are located. In many colonies none of the 

 zooids appear to have reproductive organs. Fig. 54 was drawn from 

 such a specimen. 



This form is very widely distributed at Bermuda, occurring 

 attached to the under side of stones near low water mark, and in 

 deeper water on the lower parts of corals and gorgonians. One of 

 the specimens obtained by Goode was growing on eel grass as is the 

 common habit of Botryllus govldii Verrill of the New England 

 coast. Sluiter records this species from South Africa. 



The internal structure of the zooids in the two following forms 

 does not appear to differ from that of the typical B. nigrum. 



Var. planum, uov. 



Plate LIII. Figure 55. Plate LIX. Figure 110. 



The type specimen was obtained by Professor Verrill in 1898. It 

 covers a number of square centimeters of the surface of a piece of 

 limestone. In the preserved specimen the zooids appear of a dark 

 purplish color. Some of the mantle cells are especially rich in pig- 

 ment, giving the zooids a speckled appearance under the microscope. 

 The peculiarity of the specimen is the greatly flattened and expanded 

 condition of the colony, the zooids lying on their ventral surfaces, 

 well separated from each other, though arranged in the chai'acteris- 

 tic elongated systems of a Botrylloldes. 



The zooids themselves are much flattened and the anterior end is 

 sharply turned up. The mantle is nearly devoid of muscle fibers ; 

 it is much larger than the branchial sac, and the atrial siphon opens 

 far back toward the posterior end. 



Another specimen, incrusting a piece of coral, was obtained by 

 Prof. Verrill, in 1901, in Harrington Sound. The zooids are purple 

 in color, but lack the deeply pigmented cells in the mantle. In both 

 colonies the test-substance is transparent and nearly colorless, form- 

 ing a very thin expanded layer over the object on which the colony 

 grows. I have no notes on their colors during life. 



