242 MR. E. J. MIERS ON THE OXYSTOMATOUS CRUSTACEA. 



with the age and sex of the specimen ; and (in the case of M. peronii and M. limaris) 

 examples of widely separated species are brought together, and exist in the nationa 

 collection under the same specific name. In the case of these species I have therefore 

 considered the specimen figured by Dr. Leach the type of the species. Of M. banksii 

 no labelled specimens are now in the collection ; and I have been guided by the descrip- 

 tion alone. 



In 1825, M. Latreille, in the tenth volume of the ' Encyclopedic Methodique d'His- 

 toire Naturelle,' published an excellent article upon the genus Matuta, in which he indi- 

 cates, for the first time, what I believe to be the natural subdivisions of the genus, based 

 upon the sculpture of the external surface of the hand. He describes a new species, 

 M. doryphora, and in a footnote points out distinctive sexual characters. His essay is 

 not noticed by M. Milne-Edwards in ' L'Histoire naturelle des Crustac6s.' This natu- 

 ralist, in his second volume of the work in question (1837), admits but two species of 

 this genus, M. victor and M. lunaris, Herbst, characterized respectively by the carapace 

 being marked with numerous scattered dots or reticulating lines. 



De Haan, in the fifth fasciculus of his elaborate work on the Crustacea of the * Eauna 

 Japonica' of Von Siehold(1841), reunited under one name, Matuta victor, all the species 

 of the genus, but distinguished six varieties, to which no original names are applied — 

 although he quotes as synonyma the names of several of the species of the earlier 

 authors, as referring to them, whether rightly I am not in every case able to determine. 

 Dana, in 1852, in the first part of the ' Crustacea of the United-States Exploring Expe- 

 dition,' xiii. p. 395-6, notes the sexual differences in the striation of the ridge on the 

 mobile finger in the specimens collected by the Expedition, but adds nothing to our 

 knowledge of the species. 



Hess (1865), in the ' Archiv f. Naturgeschichte,' xxxi. p. 158, pi. vi. f. 13, described 

 and figured a new species, M. picta, from Sydney. E. Hilgendorf, in the ' Eeisen in 

 Ost-Afrika ' of Baron van der Decken (1869), figures details of a species he refers, I 

 believe, correctly to M. victor (op. cit. Crustaceen, p. 93, pi. iii. fig. 2), and adds remarks 

 upon the striated areas upon the inner surface of the hand (which, he thinks, serve the 

 purpose of producing sound), and upon the specific distinctness of M. victor and M. 

 lunaris. 



Lastly, in 1874, M. Alphonse Milne-Edwards, in the ' Nouvelles Archives du Mu- 

 seum,' x. p. 54, reunites, under the name of M. victor, all the species of earlier authors, 

 remarking that it is impossible to admit the numerous species proposed by different 

 authors, every intermediate degree being found between forms which at first might 

 appear distinct. 



I have endeavoured to retain the names of the early authors for the species hereafter 

 described, wherever possible ; but their identification is often a matter of considerable 

 difficulty, owing to the insufficiency of the descriptions and the inaccuracy of the figures. 

 The species of the genus Matuta are distributed throughout the whole Oriental region ; 

 but I am not aware that any have been recorded from any other of the great geogra- 

 phical areas. 



