98 PORTUNID^. 



LeacVs name for the species, in which I have been pre- 

 ceded by Mr. W. Thompson, of Belfast, I beheve that I 

 follow the strict law of priority ; as the early parts of the 

 " Malacostraca Britanniee " were published in 1815, and 

 Risso's " Histoire Naturelle des Crustaces des environs de 

 Nice *" not until the following year. The specific name 

 Rondeletii is retained by Risso in his Natural History of 

 Southern Europe, which was published in 1826, so that 

 he was either not aware of Leach's figure, or not satisfied 

 of its specific identity with his own species. Milne Ed- 

 wards has also kept Risso's name against the law of 

 priority of description. 



The carapace is four-fifths as long as it is broad ; con- 

 siderably raised, the regions distinct, the surface granu- 

 lated ; the anterior portion slightly scabrous ; the anterior 

 margin describing nearly a semicircular arch, of which the 

 front forms a continuous portion ; latero-anterior margin 

 on each side armed with five teeth, including that at the 

 external canthus of the eye ; the fourth being the smallest, 

 and the fifth prominent and acute. Front entire, except 

 in the variety named by Dr. Leach emarginatus, in which 

 it is slightly excavated, the margin granulated and fringed 

 with rather long hair ; the posterior portion of the cara- 

 pace broad, the posterior margin nearly straight ; orbits 

 with two fissures on the upper margin, and one beneath. 

 The anterior feet in the male very robust ; the wrist armed 

 with a single prominent and acute spine ; the hand with 

 a double carina on the superior edge, each terminating in 

 a small tubercle ; the fingers strong, armed with numerous 

 tuberculous teeth, and each having two carinas on the outer 

 surface, and a carina and a groove on the inner ; the re- 

 maining pairs of feet rather slender ; the third and foui'th 



