CARCINOLOGICAL STUDIES. 



75 



Leyden. Berlin. 



60 mm. 58 mm. 



61 



55 



58 



51' 



Length of the meropodites of the second 



right pair of ambulatory legs . 

 Length of the meropodites of the third 



right pair of ambulatory legs . 

 Length of the meropodites of the fourth 



right pair of ambulatory legs . 



As I already observed above , the two specimens do not 

 fully agree with one another as regards the dimensions. 

 Firstly in the Leyden specimen the distance between the 

 extraorbital teeth is a little larger in proportion to the 

 length of the cephalothorax and to the distance between 

 the third antero-lateral teeth than in the specimen of 

 Berlin. The ambulatory legs seem to be comparatively a 

 little shorter in the specimen of Herbst than in that of 

 Leyden and the meropodites of the last pair of legs are 

 comparatively a little longer in proportion to those of the 

 other legs in our specimen than in that of Herbst. 



Dr. Hilgendorf adds that the meropodites of the left 

 legs of the Berlin specimen are all together one milli- 

 metre shorter than those on the right side. 



The four species of the genus Geryon may be distin- 

 guished as follows: 



Lateral margins with five teeth. Front exactly as broad 



as the orbits quinquedens Smith. 



Antero-lateral margins a little 

 shorter than the postero- 

 lateral and concave between 

 the antero-lateral teeth 



=^ o S^ 



Co . u 



ÏH (i3 cu 



_g -M ^ 



CO -4^ O 



1—1 ;h 



.J2 



Antero-lateral margins 

 slightly convex between the 

 antero-lateral teeth, which 

 are comparatively . 



tridens Kröyer. 



large: 

 longipes A. M. Edw. ^) 



small: 

 trispinosus Herbst. 



1) Victor Carus (Prodroraus Faunae Mediterraneae. Pars II, 1885, p. 522) 

 quotes Geri/on longipes as identical with Geryon tridens. 



!N'otes froEu th.e Leyden JMuseuxa , ^ol. iXJLI. 



