lxxxii 



THE VOYAGE OF H.M.S. CHALLENGER. 



The localities of this latter genus appear to be more numerous within the warmer or 

 tropical latitudes, as may be seen from the accompanying table : — 



Of these localities, Japan, that is about 40° N. lat., is the most northerly range, 

 whereas the species of Palinurus in which the flagella of the first pair of antennae 

 are short have been taken, with the exception of the little known species Palinurus 

 longimanus, south of the Cape of % Good Hope or north of the latitude of the Japanese 

 Islands. 



In passing to a consideration of the closely allied genera of Scyllariclae it is necessary 

 to notice the ancient form of Cancnnos claviger, Minister, found in the White Jura of 

 Bavaria, which possesses much of the character of the Scyllaridaa, but has the outer pair of 

 antennae multiarticulate as in the Palinuridae, but reduced in length to about that of the 

 carapace, and has the flagellum increased in diameter to a greater degree than that of the 

 peduncle, as if it were in anticipation of assuming the broad flat uniarticulate condition of 

 the Scyllaridse. The body of the animal itself is apparently broader and more depressed 

 dorsally than in the Palinuridas. This genus leads us on to the Scyllariclae, of which 

 the earliest form appears to have been found in Thenops scyllariformis, Bell, of the 

 London Clay. 



This family in the recent seas is remarkable for the broad and foliaceous character of 

 the flagellum of the second pair of antennae, which, instead of being multiarticulate, 

 consists of a broad and uniarticulate disc-like plate. 



Most of our recent species are inhabitants of the warmer zones. Ibaccus peronii has 

 been taken as far south as Australia, but all the other species appear to be inhabitants of 

 the tropical regions. One species of the genus Scyllarus has been taken as far north as 

 Japan, or in latitude 40°, and the closely allied form Arctus has been found as far 

 north as lat. 50°, it being common on the French coast, and on the islands at the 

 entrance to the English Channel, and it has occasionally been found as far north as 

 the shore of Cornwall and Devon, and sometimes has even been taken in Plymouth 

 Sound. 



