W. G. Van Name — Bermuda Ascidians. 399 



but sometimes by the left side. Its most conspicuous character is 

 the abundant blue-black pigment which colors the test and many of 

 the internal organs as well. In very young specimens the test is 

 nearly colorless and transparent, but the dark pigment begins to 

 appear while the individual is still very small. 



The largest specimen obtained at Bermuda measured about V0x30 mm . 

 In the West Indies it attains a considerably larger size. 



The branchial sac tapers posteriorly. The internal longitudinal 

 bars are provided with curved papilla? somewhat similar to those of 

 A. curvata Traustedt illustrated below, but rather longer and more 

 curved. They have a narrow membrane attached to the concave 

 side. According to Traustedt the papilla? are bifid at the extremity. 

 This does not appear to be common in the Bermuda specimens. 

 There are about five or six stigmata in a mesh, and the sac exhibits 

 minute undulations or plications between the internal longitudinal 

 bars. The transverse vessels alternate in size. In addition there are 

 much thicker ones at intervals. 



The tentacles are numerous and slender, of several sizes, arranged 

 with some degree of regularity. The dorsal tubercle generally has a 

 U-shaped opening. 



This species is common on the reefs and at a little distance much 

 resembles a kind of sponge which abounds there. As already men- 

 tioned, the individuals found were of small size compared to those 

 occurring in the West Indies. 



It is questionable whether this form is distinct from Phallusia 

 nigra Savigny, a European and Red Sea species. As far as I am 

 aware, the only distinction between the two is that the European 

 form has small intermediate papillae on the internal longitudinal bars, 

 midway between the transverse vessels. Both Traustedt and Sluiter 

 mention their absence in the West Indian form, and I have failed to 

 find them, even in the largest of the Bermuda specimens which I 

 examined. 



Herdman (6), though aware of Traustedt's observation, identifies 

 the Bermuda form with Savigny's species, and mentions intermediate 

 papilla? as present in parts of the branchial sac. He does not, how- 

 ever, expressly state that he found them in American specimens, and 

 later may have changed his opinion, as in his Revised Classification 

 of the Tunicata (7) he lists A. nigra Savigny and A. atra Lesueur 

 as distinct species. Phallusia violacea Gould, from Rio Janiero, 

 Brazil, may be identical with this species.* 



* U. S. Exploring Expedition, Molluska and Shells, p. 495, fig. 610. 



