154 J. WILFRID JACKSON ON 



1 have also to thank him for very generously sending me several preparations made 

 from this specimen. 



Dr BLOCHMANN considers the specimens from South Georgia and from South 

 Orkneys to be referable to L. uva, but points out certain peculiarities whereby they 

 ditter from typical examples from Burdwood Bank and elsewhere. 



From the microscope preparations it is seen that the spicuke are somewhat weaker 

 in their development than is usual ; the spicules penetrating into the bases of the 

 cirri, too, are in most places not ordinarily developed. 



In the visceral membrane (dorsal and ventral) and in the spiral arms the spiculse 

 are completely absent. They are also somewhat less developed than usual in the side 

 arms, being confined to the anterior portion of the ventral side. 



The Scotia Bay examples, therefore, present a considerable difference in the form of 

 the spiculse when compared with the characters exhibited by the examples of L. uva 

 figured by BLOCHMANN (1912, pi. ii. tigs. 16-18). 



In these latter, which come from the Falkland Islands, Magellan Straits, and Cape 

 Horn, the spiculse are normally developed in the visceral membrane, but in other 

 particulars they conduct themselves as in the above-mentioned examples. 



Unfortunately my specimens arrived too late for Dr BLOCHMANN to study them 

 before the publication of his recent report on the examples from South Georgia 

 (Swedish Expedition). He has since, however, made a careful comparison of the forms 

 from both localities, and reports that, as in the Scotia Bay examples, the spicules are 

 also absent from the visceral membrane in those from South Georgia. Consequently, 

 his remark that "the spiculse exhibit no differences" (1912, p. 3), now requires 

 modification. 



It would appear from this fact that we are possibly dealing here with an interesting 

 geographic variant, if not with an entirely new species. The study of a larger number 

 of examples, however, would be necessary before one could arrive at a definite conclusion 

 as to whether the absence of spiculaa from the visceral membrane is a constant character 

 or not. Hence it remains purely a matter of opinion whether this eastern form is to 

 be regarded as a variety or as a distinct species. 



The brachial support presents the characteristics of L. uva (see fig. 3, and BLOCH- 

 MANN, 1912, pi. i. fig. 12); the outer appearance, too, agrees fairly well with this 

 species, with the exception that the specimens are larger than usual and the character- 

 istic fine radiating striae of L. uva are scarcely perceptible. 



The difference in size in the Scotia Bay examples might, of course, be due to the 

 very shallow deptli (6 fathoms) from which these specimens came. The same 

 argument does not apply, however, to the South Georgia examples, which were 

 obtained in about 122 fathoms. 



Owing to the unfortunate omission of particulars relating to depth, etc., in 

 UKHLERT'S reports (1907 and 1908) on the specimens obtained by the French 

 Antarctic Expedition, whose area of research was off the western Antarctic continent, 



(ROY. soc. EDIN. TRANS., VOL. XLVIII., 376.) 



