78 AUSTRALASIAN ANTAECTIC EXPEDITION. 



A. MARGINATA var. nor. MCLEANI. 

 (Plate 8, fig. 90.) 



This variety differs from the species in having in some of the anterior neuropods 

 an additional partial row of 3, 4, 5, or 6 black spines, starting from below and extending 

 upwards behind the third row. In this respect it recalls the arrangement seen in 

 A. ohlini Ehlers (1901), which, however, possesses 10-20 of these spine-bearing segments 

 in place of 13 or 14 in A. marginata. 



It is true that Ehlers (1913, p. 521), in referring to a form of Aricia from the 

 Falklands Islands differing from A. marginata in having 17 such segments, expresses the 

 opinion that differences in the number of anterior segments, as well as of gill-less segments, 

 are not of importance in differentiating species in the genus. If this is the case, it is possible 

 that A . ohlini is synonymous with A . marginata, which agrees in most features with it, 

 though, according to Ehlers, the position of the gill in relation to the parapod is different, 

 for in A. oMini it is closer to the dorsal cirrus, or " lip," than in the other species; and 

 the form of the hinder parapods apparently present certain differences, though the 

 figures given by Gravier (1911, pi.' VI, figs. 72-73) for A. ohlini are quite different from 

 those given by Ehlers. 



For the present it seems better to regard the two species as distinct, though it is 

 clear that they are closely allied, and this new variety emphasises this alliance. 



The additional row of spines does not exist on all the neuropods; usually they 

 commence on the 3rd or 4th, and continue to the end of the series. In some cases the 

 third normal row is imperfect at its lower end, but not always, even in the same individual. 



The gill commences on the 6th cheetigerous segment, though in one individual it is 

 on the 7th, but variation in this respect is already known; and I note, for instance, that 

 in one specimen of A. marginata the gill is present on the 5th on one side, and on the 6th 

 on the other. 



Some of the specimens are white, others are very pale brown. 



The general dimensions and other external features are similar to those in the 

 species. 



Locality. 



Commonwealth Bay, 25 fathoms (several). 



Genus SCOLOPLOS Oersted. 



SCOLOPLOS MAWSONI sp. HOV. 



S. kerguelensis Gravier (nee Mclntosh) (1911), p. 108, pi. V, figs. 60-63. 



(Plate 8, figs. 91-94.) 



A vast number of individuals of this small species was collected at Boat Harbour 

 at depths of 2-4^ fathoms. In one bottle there are scores, if not hundreds of specimens. 



