372 GEOGRAPHICAL DISTRIBUTION. 



Eastern and Western Sides of the Tropical and Subtropical Atlantic. 



Thirty-two species of Siphonophores, excluding some doubtful records, 

 are known from the warm waters off the eastern coast of the United States, 

 i. e. from the West Indies or from the Gulf Stream, and twenty-five of these are 

 likewise known either from the neighborhood of the Canaries, from the Mediter- 

 ranean, or from the Bay of Biscay. None of the remaining seven, Diphyopsis 

 hispaniana, D. mitra, Abyla leuckartii, Anthophysa formosa, Salacia uvaria, 

 Angelopsis globosa, or Pterophysa grandis, are peculiar to the West Indies except 

 the first, and this is a doubtful species (p. 244). Anthophysa formosa and Salacia 

 uvaria are known from other parts of the tropical Atlantic, Diphyopsis mitra 

 and Abyla leuckartii from the Pacific and Indian oceans; Pterophysa grandis 

 from Malayan waters, while Angelopsis globosa is represeiated in the Pacific by 

 an extremely close ally. 



On the other hand out of forty-seven Mediterranean and east-Atlantic spe- 

 cies, over half are already known from the western Atlantic, and of those not yet 

 recorded from there, all, except Sphaeronectes irregularis, Diphyes subtilis, Agalma 

 clausi, Anthemodes ordinata, and Pterophysa grimaldii, have been found in the 

 Indian Ocean, in the Pacific, or in both. The first two may have easily escaped 

 notice in West Indian waters, indeed D. subtilis was long overlooked even in 

 the Mediterranean; Agalma clausi is represented in the Indian Ocean by a close 

 ally; Anthemodes ordinata is apparently very rare; and Pterophysa grimaldii 

 belongs to a mesoplanktonic genus. Furthermore Chun ('97b) has pointed out 

 that during the "Plankton" expedition several of the commoner Calycophorae 

 were taken regularly throughout the warmer regions visited. Thus it is evident 

 that there is no division in the Siphonophore fauna as we pass from one side of 

 the Atlantic to the other, any more than there is in the Indo-Pacific region, 

 though these are, of course, local anomalies. 



One of the most striking of these is afforded by Muggiaea atlantica. This 

 species is so far known with certainty only from British waters, and from the 

 Eastern Tropical Pacific, though it is probably recorded from the Canaries 

 (p. 186). Judging from the temperature range through which it occurs, 83°- 

 52°, there would be every reason to expect to find it as widely and regularly 

 distributed as Diphyes appendiculata; but apparently such is not the case. It 

 is unlikely that its absence from the collections made by Dr. Fowler in the Bay 

 of Biscay in July, 1900, is due to its being overlooked, because the methods 

 employed on the Cruise were unusually painstaking and thorough. At any rate 



