ON A NEW SPECIES OF PHYMOSOMA. 123 



(ii) Ph. Agassiziij which, while it occurs as far north as 

 the former species, reaches very much farther south. This 

 species stretches from Vancouver's Island down the west coast 

 of America as far as Puntarenas in the Straits of Magellan, 

 and has been found at the intermediate points of San Francisco 

 and Panama. The third species, with a somewhat unusual 

 distribution, is — 



(iii) Ph. Lovenii, which is found only in the Bergen 

 Fiord. This is still further removed from the equator than the 

 southernmost point reached by Ph. Agassizii, but it must be 

 remembered that the Gulf Stream keeps the water on the 

 west coast of Norway comparatively warm. Finally, we find 

 one species, 



(iv) Ph. granulatum, inhabiting the Mediterranean, and 

 stretching out into the Atlantic as far as the Azores. 



If we except the four species whose geographical distribu- 

 tion is described above, the whole genus is confined, with the 

 exception of Ph. antillarum, which extends to Puntarenas, 

 between the tropics, or only ventures just beyond them. 



The species just mentioned has a somewhat curious distri- 

 bution; it occurs all round the West Indian Islands, as well as 

 at Surinam and Puerto Cabello ; it then crosses over the 

 Isthmus of Panama, and is found along the coast of Chili and 

 Puntarenas. Another West Indian species. Ph. pectinatum, 

 is found on the west coast of America, and turns up again at 

 Mauritius, but has not been described from anywhere else. 

 Finally, Ph. pacificumhas a wide range, stretching from the 

 Red Sea by the Mauritius and India to the Malay Archipelago, 

 and thence to the Philippines and the Fiji Islands ; and Ph. 

 scolops has a very similar range, occurring in the Red Sea, at 

 Singapore, at the Philippines, and also off the Mozambique 

 coast. 



With regard to the bathymetrical distribution of the members 

 of this genus there is little to say ; they all live in shallow water, 

 and the greatest depth which I have seen mentioned in con- 

 nection with them is fifty fathoms. 



It is not possible to arrive at any very satisfactory results 



