10 



Wi LlLLJEBORG, 



class, we especially remark certain hill plants common to the mountains 

 of Europe and those of the antarctic Zone, but not met whith in the inter- 

 mediate tracts. Of these HOOKER enumerates Erigeron alpinus, Carex f estiva, 

 Phlenm alpinum and Trisetum svbspicatam, hut it is probable that on closer 

 examination these will be found to be nearly related but different species. 

 A remarkable example of a species common to both the Arctic and Ant- 

 arctic regions and not met with elsewhere, is afforded by the beautiful 

 and easily distinguised moss-species Usnea melaxantha, which is met with 

 in Greenland and Spitsbergen as well as in New-Zealand and the most 

 southerly portions of America. The only difference between the northern 

 and southern forms is that the latter seems more thriving and fructifies 

 richly, whereas the former is a more delicate plant and has never yet 

 been met with in a fructificating state. It is also curious that a so remar- 

 kably distinct form as the Nephroma arcticum, which is so generally met 

 with in the northern alpine and subalpine regions, should nowhere else be 

 represented by any analogous or similar form excepting at Magellan's 

 strait, where the very similar and nearly related Nephroma antarcticum is 

 met with. Among phanerogamous plants the genus Empetrum presents the 

 same phenomenon, being in the North principally represented by the E. 

 nigrum, whereas in antarctic America the E. rubrum is the prevailing 

 species, unless (as I have lately seen asserted) this latter be also found 

 in Northern America." 



We now proceed to describe the remarkable Amphipod Lysianassa 

 magellanica. 



It differs in many important features very considerably from the other 

 species included in the subfamily Lysianassina, and we are accordingly in- 

 duced to consider it as the type of a separate genus. The first basal joint 

 of the lower antennae is large and swelling, and uncovered at the side 

 of the head, and is limited above by a projecting point of the shell of 

 the head, which gives the head, when seen in profil a peculiar appea- 

 rance. The first pair of maxillae is furnished with a thin and long palp, 

 at the end of which are two or three coarse bristles or small prickles. 

 The 7 th caudal segment or caudal appendage, which is deeply forked, 

 is not provided with any moveable spine at the extremity of the lobes. 

 At least one such spine is found in all other Lysianassina which have the 

 caudal appendage forked. On account of its extensive geographical distri- 



