18 CARCINOLOGICAL STUDIES. 



7. Car disoma quadrat urn de Sauss. 



Cardisoma quadrata, de Saussure, Mém. pour servir a l'Histoire 

 naturelle du Mexique, des Antilies et des Etats-unis. ie Livraison , 

 Crustacés, p. 22, fig. 13. 1858. 



Cardisoma quadratum , S. J. Smith, in: Transactions Connecticut 

 Acad, of Arts and Sciences, vol. II, 1869, p. 16. 



One adult male from the West-Indies, collected by Mr, 

 Neervoort van de Poll , and a somewhat younger female , 

 collected at the Island of Aruba by Prof. Martin. 



These specimens have certainly reached the largest size 

 which this species may attain ; they are considerably larger 

 than those which were measured by Smith. Nevertheless they 

 present still distinctly all the characters by which this 

 species differs from Cardisoma Guanhumi. According to de 

 Saussure the distance between the external orbital angles 

 is , in young specimens , a little longer than the length of 

 the cephalothorax and measures Vg of the breadth of the 

 latter. In the female specimen the external orbital angles 

 are exactly as far distant from one another as measures 

 the length of the cephalothorax , and in the male the length 

 of the cephalothorax is a little larger than the distance 

 between the external orbital angles. Both in the male and 

 in the female there is a very small, though distinct epi- 

 branchial tooth at a short distance behind the acute 

 external orbital angles , and the raised line defining the 

 antero-lateral margins is still distinctly developed in both 

 individuals. The lateral sides of the cephalothorax are some- 

 what swollen, and project but little beyond the raised lines 

 which define the lateral margins. 



The orbits are comparatively high and only little more 

 than once and a half as broad as high; they are 

 comparatively a little higher in the male than in the female 

 specimen, and a little broader than the anterior margin 

 of the front. The inferior margins of the orbits pass with 

 an obtuse rounded angle to the extra-orbital teeth. The 



Notes frona the Leyden Museum , Vol. XIII. 



