On a new English Amphipodous Crustacean. 59 



VIII. — Description of a new English A mphipodous Crustacean. 

 By the Rev. Thomas R. R. Stebbing, M.A. 



[PlateH.] 



Cyproidia damnoniensis , n. sp. 



In the fourth volume of the ' Proceedings of the Linnean 

 Society of New South Wales' (1880), Mr. W. A. Haswell 

 instituted the genus Cyproidia with two species (C. ornata 

 and C. lineata), which he placed in the family Gammaridaa. 

 In his c Catalogue of Australian Crustacea ' (1882) he has 

 assigned the genus to a subfamily Cyproidides, defined as 

 having the first two side-plates of the peraeon very small, the 

 next two very large, and the two following small. Of the 

 genus itself he gives the following description : — 



" Body broad, Pereion and pleon of equal length. Coxas 

 of gnathopoda very small. Coxas of the first and second pairs 

 of pereiopoda enormously developed and cemented together to 

 form broad and deep lateral shields, concealing almost entirely 

 the gnathopoda and pereiopoda, and extending forwards to 

 the sides of the cephalon, and backwards as far as the poste- 

 rior border of the sixth segment of the pereion, excavated 

 posteriorly for the shallow coxas of the third pereiopoda. 

 Coxaa of the last two pairs of pereiopoda very small. An- 

 tennas subequal, superior without an appendage. Mandibles 

 with a palp. Maxillipedes unguiculate; both basos and 

 ischium armed with small squamiform plates. Gnathopoda 

 subcheliform. Pereiopoda slender. Posterior pleopocla bi- 

 ramous. Telson single." To this he appends a note : — 

 " The coxae of the third and fourth pereiopoda are not amal 

 gamated, as erroneously stated in the original description, but 

 that of the fourth pair is entirely rudimentary and covered by 

 that of the third." 



In the year 1882 the genus Stegoplax was founded by Prof. 

 G. O. Sars, and assigned to his family Amphilochidas, which 

 coincides with the subfamily Amphilochinas of Axel Boeck's 

 classification. This genus, like Cyproidia, is characterized 

 by the enormous development of the third and fourth pairs 

 of side-plates in the peraeon and the rudimentary structure of 

 the first and second pairs ; to which characters are added the 

 narrow linear form of the first or basal joint in the third and 

 fourth peraeopods. The mandibles are described by Professor 

 Sars as having a tolerably large molar tubercle, but a minute 

 palp. 



It is, I think, tolerably obvious that the two genera Cy- 



