1880.] NATURAL SCIENCES OE PHILADELPHIA. 207 



Genus HETEROGRAPSUS Lucas, 1849. 

 {Paeudograpsus, pars, Edw., Dana: Hemujrapsus Dana. 



Carapax arcuate, front inclined, antero-lateral margins dentate- 

 External maxillipeds nearly closing. The meros as long or longer 

 than broad, and bearing the palpus on the middle of its anterior 

 border, the exognath narrow. 



As the distinctions between the species are mainly comparative 

 and the descriptions of authors are very brief, no sj'nopsis can 

 be given. The species may however be divided into two sections, 

 according to the number of teeth on the antero-lateral margin. 



A. Antero-lateral margin inth tico teeth behind the orbital angle. 



H. Incasii Edwards. 



Heterograpsus sexdentatus Lucas, Exploration Algiers, 1, p. 19, PI. II, 



f. 4 (1849), (nee Edwards^. 

 Heterograpsus lucasii Edwards, Ann. Sci. Nat., Ill, xx, p. 193 (1853). 



Carapax regularly arcuate, epigastric lobes but slightly indi- 

 cated. Front four-lobed. Antero-lateral margin with two promi- 

 nent, narrow, acute teeth. Chelipeds without spines or tubercles, 

 the hands of the male are smooth and rounded, in the female thej' 

 have a double crest above and two elevated lines on the outer 

 surface. 1 Ambulator}' feet slender, naked ; dactyli long and 



slender. 



Algiers! (Dr. T. B. Wilson) ; Candiu (Edwards). 



H. sexdentatus Edwards. 



Cyclograpsus sexdentatus Edwards, Hist. Nat. Crust., ii, p. 79 (1837). 

 Hemigrapsus sexdentatus Dana, U. S. Expl. Exped., Crustacea, p. 348, 



PI. XXII, f. 2 (2850). 

 Heterograpsus sexdentat^ts Edwards, Ann. Sci. Nat., Ill, xx, p. 192, 

 PI. vii, f. 7 (1853). 



Carapax arcuate, surface uneven, laterally granulate. Epi- 

 gastric lobes prominent. Front straight. Antero-lateral margin 

 with two teeth behind the orbital angle, the teeth broad, the 

 emarginations narrow. Chelipeds without spines or tubercles. 

 Hands small, fingers excavate. Ambulatory feet moderate, naked ; 

 dactyli short and stout. 



Australia! (E. Wilson) ; Neic Zealand! (Dr. T. B. Wilson) ; Bay 

 of Islands (Dana). 



1 Milne-Edwards (1. c, p. 192,) divides this section of the genus into 

 two groups, one with the hands roiuided and without longitudinal cre.sts, 

 the other with cre.sts a division which evidently cannot be maintained. 



