274 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



4"2f!mm., of which 1"12 mm. goes to the trunk; it is the smallest 

 known member of the genus, xippearances point to the Southern Polar 



Pycnogontim aiirUineatujn sp. n. 



1. Dorsal view of the entire animal. 



2. View of right side with legs removed. 



Regions being the headquarters of the genus Ammothea, from which 

 various species may have radiated northwards. J. A. T. 



Movements of Heart and of Breathing in Spiders.— Y. Willem 

 (Proc. Sect. Science B. Acad. Amsterdam, l'J17, 19, 162-7, 2 figs.). 

 A spider {E^mra) fastened by the thoraxshows an oscillatory movement 

 of the abdomen and of the palps. The posterior point of the abdomen 

 moves upward and downward with a rhythm of 130 movements a 

 minute. This is due to (1) the tension' of the curved aorta under 

 increased internal pressure; and (2) the increased curve of the peri- 

 cardium during the systole of the heart when the pressure of the blood 



