the Species of Umnona. 3S5 



a large spine witli a sing-le row of comb-like teeth, similar to 

 tLe one described by Caiman in L. andreivsi. I find, how- 

 ever, that this comb-like spine is present also in L. lignorum 

 and in L. antarctica. Tlie meral and carpal joints and the 

 base of the propod bear small blunt tubercles, similar to those 

 in L. lignorum, though less prominent. 



Tlie remaining legs appear to be similar to those of 

 L. Ugnormn, and as in that species the accessory spine on tiie 

 inner side of the dactyl is simple. The meral and carpal 

 joints of the anterior legs are provided with blunt spines 

 or tubercles as in the first pair. Caiman states that in 

 L. andrewsi none of the distal segments are provided with 

 tubercles or blunt spines; the development of these tubercles 

 in the specimens of L. segnis and of L. lignorum that I have 

 examined seems to be subject to some variation, as they are 

 sometimes more prominent than others, and tiiey appear to 

 be best marked in the larger specimens ; Caiman's specimens 

 of L. andreivsi were only about 2 mm. in length, and their 

 small size may account for the absence of these tuberc'es. 

 The tubercles are present in L. antai-ctica and apparently also 

 in L. pfeferi ; indeed, all the perseopoda of the last species, 

 as described by Stebbing, seem closely similar to those of 

 L. lignorum and L. segnis. In all the species all the legs are 

 provided with prominent pectinate spines,simi]ar and similarly 

 arranged to those in L. lignorum-, these doubtless serve some 

 useful purpose in connection with the lite of the animal, 

 though it is not easy to see what their precise function is. 



The pleopoda do not appear to differ from those of 

 L. lignorum ; the last pair has the niaigins of both plates 

 free from seta. The uropoda (fig. 5) have the inner ramus 

 slightly shorter than the stout peduncle and ending in a tuft 

 of long setas ; the outer ramus is small, curves downwards, 

 and has the extremity unguiform; the peduncle is produced 

 between the rami into a subacute piojcction. The peduncle 

 bears on the lower side, near its outer margin, a longituciiiial 

 row of long plumose setaj, as in L. lignorum and L. pfefferi, 

 but has the outer margin almost smooth instead of being 

 tuberculated as in L. lignorum ; in some specimens of that 

 species that I have examined, however, these tuberculations 

 are by no means distinct. In his table giving the distinctions 

 between the species, Stebbing describes L. lignorum as 

 having the outer ramus of the uropods " unguiform," and 

 thus distinguished from the other species in his list (L. segnis, 

 ]j. antarctica, and L. pjfcfftri), in which it is not unguiform. 

 Wiiether the outer ramus in L. segnis should be called ' 

 " unguiform" or not is largely a matter of definition, but it 



An7i. cC- Mag. N. Hist. Ser. 8. Vol. xiii. 27 



