ANTARCTIC MARINE 



giant of its kind. Seven tropical Monhysteras taken at random from 

 the writer's collections prove to average hardly 50 per cent longer 

 than the average of the seven polar Monhysteras here described. 



There is little evidence that these polar species are less fecund than 

 those found elsewhere. It is hardly conceivable that the body tem- 

 perature of the marine polar species is higher than that of the water 

 in which they live, namely, near the freezing point of fresh water, and 

 yet, in spite of the freezing temperature, and the long polar night, 

 nematode protoplasm seems to glide on through its mitosis dance to 

 much the same purpose as if bathed in equatorial light and ensconced 

 in the warm pools of tropical reefs. 



Through long residence and much travel in Pacific regions the writer 

 has had unusual opportunity to become acquainted with their charac- 

 teristics, and having at 

 times paid particular 

 attention to the marine 

 nematodes of these re- 

 gions (map), is able 

 from personal observa- 

 tion to say concerning 

 the nematodes Lieu- 

 tenant Shackleton's 

 expedition brought 

 from the far South, that 

 in nothing are they 

 more remarkable than 

 in the striking resem- 

 blance they bear to 

 forms found in the 

 warmer parts of the 

 water hemisphere. 



Their nearest known 

 relatives are found in 

 Xew Zealand and the 

 islands off the coast of 

 the south end of South 

 America. Nearly all of 

 the Shackleton species belong to known genera, and the two new 

 genera are nearly related to genera already known, Aplectus to the known 

 Plectus and Austronema to the known Monhystera. 



Fig. 1. Marks indicate about twenty of the 

 author's Xematode Stations Xorth American, Asi- 

 atic, Australasian and Oceanic at the great ma- 

 jority of which he has made personal examinations, 

 and with the nematode fauna of which the Shackle- 

 ton nematode collections are compared. 



