GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1513 



2. TORRID ZONE SECTION. 





Species in the 

 Torrid zone. 



Species in the Tempe- 

 rate and Frigid tones. 



10 



2 



. 12 



1 



8 



1 



. 31 



7 



4 



2 



3 







1 







. 3 







2 







. 32 

 1 



19 (1 frigid) 

 



3 



1 



19 



12 



Astacidea. 



Scyllaridae, except Arctus, 

 Palinuridae, Gr. Panulirus, 

 Caridea. 



Atyinae, 

 Palaemonidae. 



Alpheinse, Gr. Alpheus, 

 Palaemoninae, Gr. Pontonia, 

 (Ediptis, 

 Harpilius, 

 Anchistia, 

 Palxmonetta, 

 Palaemon, 

 Hj/menocera, 

 Oplophorinae, 

 Penseidea, 



XXII. Considering the Scyllaridae and Palinuridae as the Macroura 

 highest in grade, this division of the Podophthalmia appears at first 

 to have its superior developments in the tropics. But it may still be 

 questioned whether this is altogether true. The Palinuridae include 

 two genera, one Palinurus, mainly a cold-water genus, the other Panu- 

 lirus, a warm-water or Torrid zone genus : and is the Torrid zone 

 genus the superior in rank, as should be the case, if the tropics are 

 the most congenial to the highest Macroural developments? Pali- 

 nurus has the outer antennae nearly in contact at base, and the 

 flagella of the inner antennae are very short ; Panulirus, the warm- 

 water genus, has the outer antennae remote at base, and the flagella 

 of the inner antennae very long. The genera are thus characterized 

 by marks analogous to those that distinguish the higher and lower 

 species among the Brachyura, or that exhibit the superiority of the 

 Brachyura as a class over the Macroura ; and if such evidence is here 

 to be regarded, the cold-water genus, Palinurus, is the higher in rank. 

 Moreover, the aspect of the Palinuri, the harder shell and more com- 

 pact body, strike the eye at once as indicating their higher character. 

 In size, they are not at all inferior; they even exceed the Panuliri in 

 bulk if not in length. Among the Palinuri, one species is afforded by 

 the warm seas of the West Indies; but it is not half the size lineally, 



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