Classification of the Thalassinidea. 5oL 
Key to the Subgenera of Callianassa. 
I, Eyes flattened against one another, with the cornea 
usually on the outside. 
1. Propodite of the third leg without a lobe on the 
HMM CIMA SGI ye eens vic-sye cute atu tds a> a eee Calhactites. 
2. Propodite of the third lex with a lobe on the 
hinder edge, 
a. Telson long. 
a, Third maxillipeds narrow ..... isaataneteraes » Cheramus. 
b. Third maxillipeds very broad.........0.- Trypea. 
Gehelson short and-broad™ 2242s sesesscee ene Callichirus. 
If. Eyes rounded, bearing the cornea at the end....  Scallasis. 
The genealogical relations between the genera of Thalassi- 
nidea are probably those shown in the following tree :— 
Callianassa. Glypturus. 
Gebicula. 
Callianidea. 
Upogebia. 
Lhalassina, 
Axiopsis. Axius. Scytoleptus. 
Laomedia. Jaxea. = ye 
Calocaris, 
