26 PROCEEDINGS OF THE NATIONAL. MUSEUM. vol.64. 



equator, and, as stated later, the author is incUned to think that 

 there must be some mistake about this species. 



The genus Boeckella occm-s in Austraha, Tasmania, New Zealand, 

 in South America from Tierra del Fuego to Lake Titicaca, and in the 

 Falkland Islands. There are 8 species in Australia, 3 in Tasmania, 

 2 in New Zealand, 6 in South America, 1 in the Falklands, and 1 in 

 Mongolia. One species, B. triarticulata, has been found in both 

 Australia and New Zealand. With this exception, of Australia, 

 New Zealand and Tasmania, each has its peculiar species. The 

 South American species are all distinct from those of Australia, New 

 Zealand, and Tasmania. One South American species, B. michaelseni, 

 has been found in the Falkland Islands. With this exception none 

 of the South American species has been found away from the conti- 

 nent. B. gracilipes and B. occidentalis have been found in Lake 

 Titicaca and B. occidentalis and B. poopoensis in Lake Poopo. 

 The others were found in Patagonia and Argentina. 



B. orientalis found in Mongolia bears a sm-prisingly close resem- 

 blance to B. ohlonga found in Australia. The differences as shown in 

 Sars's figures are that the lobes of the last cephalothoracic segment 

 of the female are longer in B. orientalis and of a somewhat different 

 form from those in B. ohlonga, and in the left fifth foot of the male the 

 serrate lamella of the second basal segment is longer. It may be 

 a fair question whether the dift'erences should be considered more 

 than varietal. In that case we are faced with the fact that a genus 

 which, with this single exception, is confined to the southern conti- 

 nents, and there has developed into somewhat localized species, has 

 one species common to southern Australia and Mongolia. This 

 would hardly seem possible, and one can not help conjecturing whether 

 the locality labels of the collections might not have been misplaced. 



Of the 8 species of Pseudohoeclcella all but one are found in Pata- 

 gonia; this one, P. vallentini, has been found only in the Falklands. 

 Two species, P. poppei and P. silvestri, occur not only in Patagonia 

 but in South Georgia, and P. silvestri has been found also in Louis 

 Philippe Land and the Falkland Islands. P. hrevicaudata has a rather 

 surprising distribution, for besides occurring in Patagonia and 

 Tierra del Fuego it has been collected in Kerguelen and New Amster- 

 dam Island. It certainly is strange that this species should be found 

 in the islands in the Indian Ocean but not on any of the islands near 

 South America. Of course, in any discussion of the distribution of 

 these forms, it should be remembered we are speaking only of the 

 localities in which the species have been found, and that the islands 

 bordering the Antarctic have been very imperfectly explored for 

 their invertebrate fauna. 



In regard to the manner in which these species were distributed, 

 it should be said that while there is no impossibility, theoretically, 



