210 EXPEDITION OF THE "ALBATROSS," 1899-1900. 



Finally the part of the world from which the two animals come supports 

 the view that they are the same. Tliey are both from the South Pacific. 

 Hu.Kley's specimens were taken on tlie coast of New Guinea, situated in 

 Lat. 0' to 10' S. and Long. 132' to 152° W., while the specimens under con- 

 sideration in the present paper are from Station 16 A. A. Lat. 2" 38' N., 

 Long. 137' 22'. 



There are two points only in which the information at hand seems to 

 indicate rather important differences between the two forms. Huxley says 

 "a very distinct spherical auditory sac" is attached to the ganglion, and his 

 figures indicate still more distinctly than do his words that this structure is 

 much larger than it seems to be in our specimens. We assume, however, 

 that the difference is due to the fact that Huxlev studied livino; animals, 

 while we have, of course, been able to examine only preserved ones and 

 rather poorly preserved ones at that. 



The other seeming difference is in the musculature of the tail. Huxlej-'s 

 figures certainly do not indicate as wide a band of muscle on each side of 

 the notochord as is present in the specimens examined by us. As shown in 

 fig. 1 1, there is almost no muscleless zone between the outer border of the 

 muscle and the margin of the tail, while Huxley's figures show a v/ide zone 

 of this kind. So far as this fact by itself is concerned, we might suppose 

 the difference to be due again to shrinkage in preservation suffered by our 

 specimens. It seems, however, that the nniscle bands in our specimens are 

 broader relatively t<> the notochord than is Huxley's, and it is not apparent 

 that shrinkage could account for this. However, we cannot believe that in 

 view of the many strong resemblances this one apparent difference should 

 have much weight. 



It remains to say a few words concerning the name of our species. 



The name AppeiuHcuIaria Jlagdlum. applied by Huxley, not only to his 

 New Guinea specimens, but also to all the Appendicularians subsequently 

 studied by him, he adopted from Chamisso, who had given it in 1821 to an 

 animal taken by him " near Behring Sea." Oikopleura was proposed by 

 Mertens in 1831 for an animal discovered in the same region, and called 

 by him 0. chamissonis. Neither Chamisso nor Mertens defined their genera 

 with much accuracy, Chamisso being especially brief and general in his 



