258 " ENDEAVOUR " SCIENTIFIC RESULTS. 



Chun, in his ilhistrations of R. mastigophora, figures the 

 dorsal arms as showing conspicuously enlarged suckers on 

 the inner (dorsal) series only. He shows only three or four 

 pairs of the minute basal suckers, and neither describes nor 

 illustrates the lateral poekets which are so curiously developed 

 in R. australis. That his specimen could not have been too 

 immature to exhibit these features is shown by the fact that 

 in gross measurements {e.g., mantle length 31 mm.) it almost 

 exactly tallies with the example before us. Another inter- 

 esting difference is that in his specimen the right dorsal arm 

 was decidedly longer (29 mm.) than the left (25 mm.). Still 

 another difference noted between the present species and 

 R. mastigophora is in the notably smaller size (and probably 

 greater number) of the tentacle suckers. Chun (1915, p. 

 407) writes as follows : — 



" Die Tentakelnapfe sincl so winzig, class sie mit blossem 

 Auge kaum erkannt werclen konnen. Die Ausraessung ergibt, 

 dass sie einen Querdurchmesser von nur 0, 15-0, 17 mm. 

 auf weisen und damit zu den kleinsten Tentakelnapfen gehoren, 

 die wir iiberhavipt aus der Reihe der Decapoden kennen." 



Nevertheless suckers from a $ australis larger than Chun's 

 largest specimen average a diameter less than half that cited 

 by him. They must indeed rank among the most minute, 

 fully functioning, true suckers known. 



The farther I have been able to push the comparison, the 

 more sharply differentiated from one another the northern 

 and southern Rossice appear to be. The subgeneric distinction 

 here proposed between them seems but the logical step to 

 take. I shall not be greatly surprised in case a full anatomical 

 investigation requires the elevation of Austrorossia to full 

 generic rank. At present the most important differences are 

 naturally to be found in the hectocotylized arms, which, in 

 the two austral species, are constructed on an altogether 

 different plan than in such species as R. glaucopis (Loven), 

 R. molleri Steenstrup, or R. pacifica Berry. 



Family SEPIID.E. 



Genus Sepia, Linnaeus, 1758. 



Sepia hedleyi, sp. nov. 



(Plates Ixxi.-lxxii.) 



Animal rather small ; Body of only moderate width, the 

 widest central portion only slightly exceeding the anterior 

 region, but tapering rapidly to a point behind ; anterior 



