324 INVERTEBRATA OF MASSACHUSETTS. 



in C. irrordtus, not attaining the margin of the carapax, whereas in 

 C. Sayi they greatly surpass it. The hands are decidedly smaller, 

 and while they present the same lines on the external face, these 

 lines are not conspicuously granulated, much less are any of them 

 denticulated ; the finger and thumb are scarcely, if at all, slate 

 colored. The dark-brown color of the markings is maintained 

 upon the limbs, or is rather a bright rose-red at the bend of the 

 wrist and along the inner face of the hand ; and the series of yellow 

 spots upon the back are much the same. The abdominal seg- 

 ments of the male are broader. 



Length 2| inches ; breadth 4 inches. 



The differences above mentioned are certainly not sexual ; and 

 it seems very improbable that they can be the effects of age. 



It is common about the rocky shores of our islands, of Cape 

 Ann, Nahant, &c. It is brought to market for food in consider- 

 able numbers. 



GENUS PLATYONICHUS, LATH. 



P. OCELLA'TUS. Carapax with five prominent, acute teeth each 

 side ; front one toothed ; wrist two spined, and one on the anterior 

 angle of the hand above ; last joint of the hind feet rounded at tip. 



Cancer ocellatus, HERBST; Cancr,, pi. 49, f. 4. 



Platyonichus ocellatus, LATH. ; Encyc., xvi. 162. MILNE-EDW. ; Hist. Nat. des 



Crust., i. 437. 

 Portunus pictus, SAY ; Journ. Acad. Nat. Sc., i. 62, pi. 4, f. 4. 



This is usually called the Sand- Crab, and is a beautiful species. 

 The number of teeth at the sides, with the flattened hinder feet, 

 are its obvious distinctive marks. It is not often seen near Bos- 

 ton, but is more common in more open seas. I have not seen 

 the figure of Herbst, but rely on the authority of Latreille and 

 Milne-Edwards. 



GENUS LUPA, LATH. 



L. DICA'NTHA. Carapax transverse, with nine sharp teeth on 

 each side, the last one very long ; front three toothed ; arms three 

 spined ; posterior feet flattened. 



Crabe de 1'Ocean, DEGEER ; Hist, des Insectes, vii. tab. 26, f. 8-11. 

 Portunus pelagicus, Bosc ; Crust., i. 22, pi. 5. f. 3. 



