16 W. A. HERDMAN. 



on a fold, with that of M . impura, does not show the characteristic knob-like processes 

 of that species figured by Dr. Traustedt. 



This single specimen of Molgula concomitans has a specimen of Molgula longicaulis 

 attached by the lower half of its long stalk near the anterior end (see fig. 1, B and 

 fig. 3). 



ASCIDIHXE. 



CORELLA EUMYOTA. 



(Plate III., figs. 1-6.) 



CoreHa eumyota, Traustedt, Vid. Medd., 1881, p. 271. 

 Corella novara, v. Drasche, Denk. Ak. Wien, xlviii., 1884, p. 382. 



Corella antarctica, Sluiter, Bull. Mus. Nat. Hist. Paris, xi. (1905), p. 471 ; id., Exp. Ant. Fran?. 

 (Charcot), p. 31. 



Locality. Auckland Islands, Laurie Harbour ; various dates, March, 1904 ; nine 

 specimens ranging from 1 8 to 3 cm. in length. 



External Appearance. Body elongate-ovate, with the branchial aperture at the 

 narrower anterior end and the atrial about half-way back, both on prominent siphons 

 (Plate III., figs. 1-3). Attached by the greater part of the right side. Posterior end 

 rounded. Surface smooth. Colour yellowish grey. 



Test thin, cartilaginous to membranous, translucent, easily torn. 



Mantle moderately muscular, recalling that of an Ascidia ; sphincters well 

 developed. 



Branchial Sac with the spiral stigmata short, and traversed by many connecting 

 radial or irregular short, wide, thin-walled vessels (fig. 6). Internal bars narrow, 

 supported on triangular connecting ducts. 



Dorsal Lamina represented by stout tentacle-like languets, with occasional shorter 

 ones alongside (fig. 6). 



Tentacles numerous and closely placed. There are about thirty large and at least 

 thirty much smaller placed between (figs. 5 and 6). 



Dorsal Tubercle simple, crescentic, with the horns more or less incurved. There 

 is no peritubercular area, but behind the tubercle is a very large epipharyngeal languet 

 with a deep groove (fig. 6), which forms the beginning of the series of dorsal languets. 



I agree with Drs. Sluiter and Michaelsen in considering that Traustedt's Corella 

 eumyota, from Bahia and Valparaiso in South America, is the same species as Dr. von 

 Drasche's Corella novarse, found during the ' Novara ' Expedition at St. Paul's Island 

 in the Indian Ocean. But I would go further, and suggest that Sluiter's Cordla 

 antarctica, obtained during the ' Charcot ' Expedition at " He Booth Wandel, 

 40 metres," is merely a larger, more polar, form of the same variable species ; and in 

 that case I would include also these smaller forms collected by the British Expedition 

 at the Aucklands. 



Two courses are open to us in such cases: (l) to include all the closely related 



