APPENDIX. 
411 
Leach) as A. fluviatilis of Europe, and A. affinis of North 
America, with an elongated rostrum, and A. Bartonii of 
North America, with a short rostrum. 
B. The central caudal lobe continued hard and calca- 
reous to the end, as Astacus Franklinii of Van Diemen’s 
Land, and A. Madagascar iensis of Madagascar ; both have 
a very short beak, and the second abdominal ring spinose. 
C. The central caudal lobe continued or only slightly 
divided on the middle of each side ; but it and all the lateral 
lobes are thin and flexible at the hinder parts, as Astacus 
quinque-carinatus , and A. bicarinatus of Australia, and 
A. Chiliensis of Chili. 
