MR. E. J. MIERS'S REVISION OP THE HIPPIDEA. 313 



^^at. Animaux sans Vert. v. p. 218, 1818), observing the external 

 relationship of the Hippidce with Banina, arranged them with 

 the latter genus in a distinct section of the family, characterized 

 by the lamellated terminal joints of the legs. 



M. H. Milne-Edwards (Hist. Nat. Crust, ii. p. 167, 1837) 

 considered the Hippiens a distinct tribe of the family Pterygures 

 of his Crustacts Anomoures, but regarded them as allied to the 

 Haninidce (p. 198). 



De Haan (" Crustacea," in ' Fauna Japonica,' dec. vi. p. 195, 

 1849) retains in a somewhat wider sense the division Anomala of 

 Latreille, in which he includes the Hippidea, recognizing (p. 136) 

 their relationship to the Raninidce in external appearance and the 

 form of the legs, from which, however, he points out they are 

 widely separated in the form of the pterygostomian regions, number 

 of the branchiae, and characters of the sternum and postabdomen. 



By Dana (Crustacea in U.S. Explor. Exped. xiii. pp. 51 & 

 402, 1852) a very different view is taken of the affinities of these 

 animals. This author traces with great care and accurate know- 

 ledge the relations of the different groups of Anomura with the 

 higher Brachyural types, of which they are severally degraded 

 forms, showing that they may, with equal propriety, be classified 

 {a) as in a linear descending series they deviate from the 

 Brachyural to the Macrural type, or {h) according to their 

 respective natural affinities with the higher Brachyural sub- 

 tribes. In the former system the Hippidea are ranked by him 

 with the PorceZZamWe«, as constituting the second section, ^wo- 

 moura media, of the tribe Anomoura ; in the latter they are classed 

 as Anomoura Corystidica, immediately beneath the Corystoideay 

 which latier are undoubtedly Cancroid Crustacea. "With all defer- 

 ence to the opinion of the distinguished American naturalist, I must 

 regard the older view of their affinities as the more correct. 



Although in their elongated carapace and antennae the Hippidea 

 have a considerable resemblance to certain of the Corystoidea, as 

 will be seen, e. g., by comparing the Chilian BlepTiaropoda spini- 

 mana and Pseudocorystes sicarius, I believe their true affinities 

 are with the Oxystomatous Brachyura, through the Eaninidce. 

 They resemble these latter in their narrow and elongated form, 

 natatorial legs, and, in the case of the AlhuneidcB, in the high and 

 laterally compressed hands of the anterior legs, which altogether 

 resemble those of the Oxystomatous Calappa and allied genera. 

 On account of the imperfect definition of the buccal cavity, it is 



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