41 



son for hypothesis, which geological researches perhaps 

 will clear up in the future. 



Spherilloninae. 



Mandibularum lacinia interior mobilis appendice prima 

 latiore, molari. 



Maxillse prioris paris*) endopoditum penicillis ambobus 

 brevibus, ovalibus, crassioribus. 



Oculi plerumque ipsum marginem lateralem capitis 

 occupantes. 



Conspectus generum, 



a. Capitis partes pleurales linea marg^inali verticali utrinque decur- 

 rente manifesto discretae, 

 Flagellum antennarum 3-articulatura. 

 Trunci segmentuiu 1. epimeris integris. 



Uropodes producti, telsuru superantes. Exopodituni longuiu, api- 

 cale, scapo multis partibus longius. 

 b. Pleopodum rami operculares tracheis nullis. 



1. PseudopMloscia. 3 species. 



bb. Pleopodum rami operculares tracheis instructi. 



2. Arhina. 1 species. 



aa. Capitis partes pleurales concretse; linea marginalis verticalis utrinque 

 ad oculos ssepe ad epistoma producta. 

 b. Flagellum antennarum 3 articulatum. 

 c. Trunci segmentum 1. post fissum. 

 8, Suarezia. 1 species. 



cc. Trunci segmentum 1. integrum. 



*) I have before, obsequious to Dr. H. J. Hansen, called the first pair 

 of Maxillae »Maxillulse« in accordance to the Antennulae; now I 

 dare not use this term for fear of bringing confusion, if it should 

 appear, that the Antennulae are really the second pair of Antennae, 

 what at present seems to me to be probable, and also the Anten- 

 nultR in the Crustacea are homologous with the Antennte in the 

 other Arthropoda. 



