2 ME. E. J. MIEES ON THE IDOTEID^, 



Latreille, in 1829*, divided the Isopoda into six sections, and 

 included in his fourth section {IdoUides, Leach) the three genera 

 Idotea, Stenosoma, and Arcfurus. 



Milne-Edwards, in 1840t, in his great work, united under the 

 designation Idoteides the three genera Arcturus, Idotea, and An- 

 tlmra, including in Idotea the various genera proposed by Leach 

 and Eisso, and placed Idotea and AntJmra in his subtribe Idoteides 

 ordinaires. As, however, Harger has recently shown, Idotea has 

 in reality a much closer aifinity with Arcfttrus than with AntJmra. 

 The sectional divisions adopted by Milne-Edwards, based upon 

 the number of postabdominal segments and the structure of the 

 epimera, afforded excellent characters for distinguishing the 

 species in the then existing state of carcinological knowledge. 



But fifteen species are enumerated by Milne-Edwards, and of 

 these several ai'e now shown to have been based upon characters 

 insufiB.cient to distinguish them from their congeners ; but others, 

 which later authors have proved to be distinct, are referred to in 

 the notes. 



Dana (in 1853) in his final classification of the Isopoda in his 

 work on the Crustacea of the U.S. Exploring Expedition J, enume- 

 rated five genera in the family Idoteidce, but of these two are 

 aj)parently insufficiently characterized. He associated the Ido- 

 teidce with the Olicetiliidce in his subtribe Idotaidea, but removed 

 the ArcturidcB to the Anisopoda (a group in some measure analo- 

 gous to the Anomura among the stalk-eyed Crustacea), where 

 they form, with the Anthurince, a distinct subtribe, Aniso2Joda 

 Idotceica. 



In Messrs. Spence Bate and "Westwood's standard work on the 

 British Edrioiphthalmia§ will be found a very complete account 

 of the British species, accompanied by well-executed figures, and 

 prefaced by an account of the principal anatomical and morpho- 

 logical characters of the Idoteidce. In the system of classification 

 adopted by these authors, the Idoteidce are associated with the 

 Arcturidce among the non-parasitic water-breathing Isopoda, 

 much as in Latreille's classification, and are far removed from 

 the Anfhuridce. 



One of the most important and valuable contributions to our 

 knowledge of the subject since the publication of the ' Histoire 



* In Ouvier, Eegne Animal (ed. 2), It. p, 131 (1829). 



t ' Hist, naturelle des Crustac^s,' iii. p. 121 (1840). 



X Crust, in U.S. Explor. Expedition, xiv. p. 697 (1853). 



§ ' A History of British Sessile-eyed Crustacea,' ii. pp. 114, 375 (1868). 



