1 1 



short and thin pubescence; upper margin of meropodite ending in an obtuse prominence ; 

 dactyli compressed, as long as propodites, slightly tapering and feebly curved ; the inner 

 border provided with rather irregularly-placed teeth, rising among a continuous fringe of 

 shorter or longer hairs and ending near the tip into tvvo large diverging teeth. These dactyli 

 have also been figured by Stebbing 1 ). 



Dimensions 3 ) in mm. of Leiden Museum specimen: 



Length of carapace (including rostrum) .... 9.5 

 Length of median tooth of rostrum . 



Total breadth of carapace 



Total breadth of flattened part of carapace 



Length of cheliped 



0.6 

 12.7 



13.2 



18.5 

 15.8 



Length of first pair of walking legs . 

 Length of fourth pair of walking legs 



This species is really characteristic of the subantarctic shores, whence it is recorded by 

 numerous authors. Miers 8 ) observed that it is replaced by H. ovatus in the Australian waters, 

 as far as could be traced out. 



2. Halicarcinus ovatus Stimpson. 



1858. Halicarcinus ovatus Stimpson. Proc. Ac. Nat. Sc. Philadelphia, p. 109. 



1876. Halicarcinus ovatus Miers. Cat. New Zealand Crust. p. 49. 



1886. Halicarcinus ovatus Miers. Rep. "Challenger", Brachyura, p. 282. 



1900. Halicarcinus ovatus Stebbing. Proc. Zool. Soc. London, p. 525, pi. 36 A. 



1907. Halicarcinus ovatus Stimpson, Smithson. Inst. Miscell. Coll., 'v. 49, p. 146. 



Hab. Port Jackson, Port Philip, Jervis Bay. 



Hymenicus Dana. 



185 1. Hymenicus Dana. Amer. Journ. Sc. (2) v. 12, p. 290. 



1852. Hymenicus Dana. U. S. Expl. Exp., Crust., p. 387. 



The shape of the rostrum, that covers only the bases of the antennules, the rather long 

 merus of the (slightly gaping) external maxillipeds, exceeding the ischium in length, and the 

 slender walking legs make up the principal characters of this genus *). 



Alcock 5 ) considers Rhynchoplax Stimpson synonymous, but the rostrum is altogether 

 differently shaped, and I have preferred to keep Stimpson's genus erect, referring the two species 

 of Alcock to Rhynchoplax and not to Hymenicus. In the former genus the rostrum consists 

 of three spines, directed forward ; in Hymenicus, however, it is broadly trilobate or triangular. 

 Besides, Hymenicus is exclusively New Zealandian ; Rhynchoplax inhabits the tropical shores 

 of Asia, but two species are Australian. 



1) L. c. pi. 36 B. 



2) Measured under microscope. 



3) Rep. "Challenger", Brachyura, 1886, p. 282. 



4) Dana remarks in the diagnosis: "angulo extraorbttali nullo", but in reality the outer border of the orbit is sharp and 

 slightly raised. 



5) Journ. As. Soc. Bengal, v. 69. pit 2, 1900, p. 387. 



