AND ITS INTERNAL STRUCTURES. 319 



Raine Island, 155 fathoms, in which it is more abundant than 

 I have elsewhere found it, it is by no means common. The 

 limits of its distribution, according to Brady, are Bermuda and 

 Mauritius — say, 32° north and 20° south of the Equator, Corny 

 Point is on the south shore of Australia, about 35° south latitude, 

 an extension of 15°, or 900 miles beyond its previous record. 

 Again, the specimens, according to Mr. Matthews' note, must tem- 

 porarily have existed in countless millions, judging from the area 

 of beach which they discoloured. 



Now, Corny Point is on the southern shore at the opening of 

 Spencer Gulf, which is almost a small land-locked sea running 

 due north and south. It faces north, from which direction the wind 

 had been blowing for some days. It seems evident, therefore, 

 that the sudden appearance of Gymhalopora hulloichs in such 

 enormous numbers was due to the stranding of a shoal of pelagic 

 specimens driven ashore by the winds and currents. I have 

 examined a number of gatherings from various localities on the 

 shore of Spencer Gulf and the neighbouring St. Vincent's Gulf, 

 but have never met with a single specimen elsewhere in the 

 neighbourhood. The dominant genus in the locality, as else- 

 where on the South Australian coast, is Discorhina, which 

 abounds almost to the exclusion of other types, and attains very 

 large dimensions. 



The explanation of this pelagic shoal in my opinion is in- 

 timately connected with a very thorny question — that of the 

 relationship existing between the so-called " genera " of Forami- 

 nifera. It has been more or less accepted by all rhizopodists 

 that true specific features are almost non-existent in the 

 Foraminifera. Of course for systematic purposes it is convenient 

 and even necessary to fix upon certain features for specific types ; 

 but there can be no doubt that they are more or less artificial, 

 and that environment exercises a modifying influence upon form 

 to an extent unparalleled in higher forms of life. It therefore 

 seems to me very probable that C ymhalopora, so far from being 

 a distinct genus, is only a life stage of the closely allied Dis- 

 cm^hina. Not necessarily a life stage of constant or invariable 

 occurrence, but perhaps a sexual form assumed at intervals and 

 under favourable conditions for the regeneration of a type 

 impaired by constantly repeated asexual reproduction. 



The monadiform bodies observed by Murray in small pelagic 



