OCYPODE AEGYPTIACA. 247 



For the rest , as regards the shape of the hands , of the 

 musical ridge , of the abdomen , of the legs , these varieties 

 wholly resemble one another. 



Ocypode aegyptiaca Gerst, 



Ocypode aegyptiaca, Gerstaecker, Arcliiv. f. Naturg. XXII, 

 pag, 134. 



The Museum contains nine fine specimens collected at 

 Djeddah by Mr. Kruyt (8 cf » 1 9) ^^^ ^^o others also from 

 the Red Sea , presented by Mr. Kossmann under the name 

 of the preceding species» These two species are however 

 quite different ones. Ocyp. aegyptiaca constantly and really 

 differs from the ceratopldhalma Pallas, 1" by a quite other 

 shape of the cephalo thorax , 2". by the patch of thick hair 

 occurring only on the penultimate joints of the second legs , 

 3". by the long musical ridge of the male , the transverse 

 secondary lines being equally and very much crowded over 

 the whole length and very delicate. 



The terminal spines of the eyes are very slender and ta- 

 pering, and long both in the adult male and adult female, 

 becoming tuberculiform and even quite disappearing in the 

 young. The upper surface of the carapace is very convex 

 in a longitudinal sense, everywhere granulated, more coar- 

 sely on the lateral regions , the front being large , trunca- 

 ted and granulated , the supra- orbital margin minutely den- 

 ticulate. — The external orbital angle is rather obtuse , 

 that part of the lateral margin which lies between the ex- 

 ternal orbital and epibranchial angles being convex , pro- 

 jecting more outward than the first called angle , and mi- 

 nutely denticulate ; the posterior part of the margin , like 

 the ridge that occurs on the lateral surface of the carapace 

 are granular. The large hand is a little higher than in 

 the preceding species, the under margin being more con- 

 vex and coarsely denticulate , the upper margin more acute 

 than in ceratopMhalma. The dactylopodites are rather broa- 

 der than in the preceding species. 



Notes from the Leyden IMuseum, Vol. Ill, 



