146 J. WILFRID JACKSON ON 



mantina are examples which have afforded the much-desired opportunity for studying 

 the developmental stages of the loop. 



With regard to Pelagodiscus atlanticus, although of almost world-wide distribution, 

 its probable existence in Antarctic waters has only recently been demonstrated by 

 EICHLER (1911),* who, with some hesitation, refers to this species two larval forms of 

 a Discinisca obtained in March 1903 by the "Gauss" Expedition, at a depth of 

 about 1640 fathoms in the neighbourhood of their winter station, Kaiser 

 Wilhelmland II. 



Although it is, to some extent, a matter for regret that this report is so late in 

 its publication, owing to the material having only recently come into my hands for 

 study, the long delay has not been without its compensations, as I have been able 

 to derive some benefit from, and make comparisons with, collections made by other 

 Antarctic expeditions whose reports are already published. 



Before proceeding with the detailed description of the species I must here express 

 my great indebtedness to the numerous friends who have assisted in one way or 

 another during the preparation of this report. 



To Dr F. BLOCHMANN, of Tubingen University, I am especially indebted for his 

 very material help in the discrimination of critical forms, and for his kind interest and 

 valuable assistance. To Dr W. H. DALL I am also grateful for his great kindness and 

 confidence in submitting to me a type specimen of his Macandrevia diamantina for 

 comparison with the Macandrevia obtained in 1410 fathoms off Coats Land. Amongst 

 the various friends who have assisted in sorting out the smaller Brachiopoda from the 

 Burdwood Bank material, I wish to particularly mention my colleague Mr R. STANDEN, 

 the Rev. L. J. SHACKLEFORD, and Messrs B. R. LUCAS, F.G.S., and F. G. PEARCEY. 

 And in conclusion I must tender my sincere thanks to Dr W. S. BRUCE, F.R.S.E., for 

 entrusting his Brachiopod collections to me, and for placing maps and much general 

 information at my disposal. 



List of species contained in the Scotia collections : 



Class BRACHIOPODA. 



Pelagodiscus atlanticus (King), off Coats Land, 1410 fathoms. 

 Hemithyris, n. sp., off Coats Land, 1410 fathoms. 

 Liothyrina uva (Brod.), Burdwood Bank, 56 fathoms. 



,, var. notorcadensis, nov., Scotia Bay, South Orkneys, 9-10 fathoms. 



L. blochmanni, n. sp., off Coats Land, 1410 fathoms. 

 Macandrevia diamantina, DalL, off Coats Land, 1410 fathoms. 

 Terebratella dorsata (Gm.), Burdwood Bank, 56 fathoms. 



n. sp.?, Burdwood Bank, 56 fathoms. 



Magellania venosa (Sol.), Burdwood Bank, 56 fathoms. 



* See bibliography at end of report. 

 (ROT. soc. EDIN. TRANS., VOL. XLVIII., 368.) 



