A WELL-CONSTKUCTED KEY 175 



Family Galatheidce. 



The characters are those of the legion. About ten 

 genera are included, two of which Galathea and Munida- 

 belong to the British Fauna, and, according to Dr. Hender- 

 son, have many species inhabiting shallow water. With 

 the exception of one doubtful genus, the remainder are as 

 yet known only from deep water, and it must be said that 

 according to Dr. Henderson's own report, only a few out 

 of the species of Mimida come from small depths, some 

 going down to more than 2,000 fathoms, and the majority 

 being taken most abundantly at depths varying from 100 

 to 300 fathoms. 



Galathea, Fabricius, 1793, has the carapace usually 

 free from spines, except on the anterior gastric area, but 

 furnished with furry transverse striee. The rostrum is 

 flattened, rather broad, generally having teeth on the 

 margins. The segments of the pleon are unarmed. There 

 are numerous species occurring at very varied depths. 

 They swim backwards with activity, and Mr. Couch states 

 that it is very remarkable to witness the accuracy with which 

 they will dart backward for several feet into a hole very 

 little larger than themselves, an acrobatic performance 

 which he had often seen carried out, and always with pre- 

 cision. There are five British species, all of which occur 

 also on the coasts of France, where they have been studied 

 and described very carefully by M. Jules Bonnier. He 

 supplies a very useful key to discriminate them, depending 

 partly on the shape of the third maxillipeds, and partly on 

 the presence or absence of an epipod in the limbs of the 

 trunk. The epipod, it will be remembered, is the branch 

 which issues from the basal joint of an appendage. In 

 Galathea sguamifera, Leach, Galathea nexa, Embleton. and 

 Galathea dispersa, Spence Bate, there are epipods to the 

 chelipeds and the two following pairs of limbs ; in Galathea 

 intermedia, Lilljeborg, there are epipods to the chelipeds, 

 but not to the following pairs of limbs ; in Galathea stri- 

 gosa, Fabricius, there are no epipods to any of the three 



