12 W. A. HERDMAN. 



. Alimentary Canal long, with the intestinal loop continued unusually far forwards. 

 Stomach surrounded by conspicuous glandular caeca (figs. 12 and 13). Anus with a 

 smooth, slightly thickened everted rim (fig. 12). Rectum loaded with diatomaceous ooze. 



Gonads a yellow sausage-shaped mass on each side, about 10 mm. in length, and 

 2 to 3 mm. in breadth, with a duct at the anterior end directed towards the 

 cloaca (fig. 13). 



I have pleasure in naming this new species in honour of Mr. T. V. Hodgson, who 

 showed both energy and ingenuity in his methods of collecting quantities of marine 

 animals, of many groups, from under the ice-sheet at the Winter Quarters of the 

 Expedition in McMurdo Bay. 



On trying to find the position of this species in its genus by means of the 

 dichotomising table in my " Revised Classification " * I find that its characters bring 

 it alongside M. csepiformis of N.W. European seas, and M. pedunculata from the 

 Antarctic. It agrees with M. csepiformis in being apparently unattached, but that 

 species has only been found in the northern hemisphere and is of globular shape. 

 The present species has some resemblance to Molgula maxima, described by Sluiter 

 from Dr. Charcot's Antarctic expedition (He Booth Wandel, He Anvers, 30-40 metres). 

 It also recalls my own M. pedunculata from the ' Challenger ' collection, found to the 

 South of Kerguelen Island at a depth of 150 fathoms ; and I notice that Sluiter states 

 that his species may possibly be the same as my M. pedunculata. There is no doubt 

 that all three are closely related forms, but I believe that, with our present knowledge, 

 they had better be treated as distinct species. The easier course would no doubt be 

 to say that these forms probably all belong to the one species, but so long as any 

 distinguishing features can be pointed out, such a statement would be an erroneous 

 identification. The more scientific course is surely to define such differences as we can, 

 and leave it to our successors to dispose of these if they are able. We place before 

 them the evidence for three species, which possibly they, with fuller knowledge, may 

 be able to unite. , 



From the ' Challenger ' M. pedunculata the ' Discovery ' specimen differs in 

 external appearance, in shape, in having the atrial aperture terminal, in the consistency 

 and thickness of the test, in the number of bars in the branchial sac, and in the position 

 of the dorsal tubercle ; there are also minor differences in almost all organs. Sluiter 

 has given the points in which his species differs from M. pedunculata ; and I can add 

 that the present species differs from M. maxima in the shape of the body (although the 

 relative position of the apertures is the same in both), in the number of bars between 

 the branchial folds, and in the tentacles. 



* Journ. Linn. Soc., Zool., xxiii., p. 568. It is not always possible to identify species absolutely by sucb 

 tables. They were not put forward for such a purpose (see footnote on p. 559). They serve, however, to 

 indicate the position in the genus, after which the original descriptions should be consulted. 



