144 DE. J. G. DE MAN ON THE PODOPHTHALMOTJS 



G'^l'ius Metopogeapsus, M.-Edw. 



81. Metopogeapsus messoe, Forsh. (Pi, IX. fig. 11.) 

 Cancer messor, ForsJc I, Descrvpt. Animal, etc. p. 88. 

 Grapsus messor, Milne-Edwards, Hist. Nat. Crust, ii. p. 88. 

 Metopograpsus messor, Milne-Edwards, Ann. Sci. Nat. 3 serie, t. xx. 

 p. 165. 



Grapsus (Pachygrapsus) aethiopicus, Hilgendorf, Crustaceen von Ost- 

 Afrika, in Baron v. d. Decken's Reisen, p. 88, Taf. iv. fig. 2. 



Metopograpsus messor, Hilgendorf, Monatsber. d. K. preuss. Akad. d, 

 Wiss. Berlin, Nov. 1878, p. 808; Miers, Crustacea of Rodriguez, p. 5. 

 Two specimens were collected at Elphinstone Island. 

 We are indebted for a very good figure of this species to 

 Dr. Hilgendorf, who erroneously described and figured Metop. 

 onessor as a new species, under the name of G-rapsus cethiopicus. 

 The two Mergui specimens fully agree with his figure. The pro- 

 portion of the distance between the external orbital angles to the 

 length of the carapace (the front included) is as 30 : 22 in the 

 male of this species, the cephalothorax being more enlarged than 

 in M. maculatios and JK. pictus. The front is comparatively a 

 little less enlarged than in 31. maculatus, the proportion of the 

 distance between the external orbital angles to the breadth of 

 the front (measured between the eye-peduncles) being in M. 

 messor as 30 : 19, but in M. maculatus as 30 : 20. 



The anterior margin of the front is feebly siuuated in the 

 middle, exactly as figured by Hilgendorf, I. c. fig. 2 h. 



The form of the male abdomen also agrees with that figure, 

 though the penultimate joint in the Mergui specimens appears a 

 little longer in proportion to its breadth. 



The hands are somewhat unequal ; their outer surface is very 

 convex and appears perfectly smooth, though a little minutely 

 punctate (when seen under a magnifying-glass), except at the 

 upper margin and near the articulation with the wrist. The upper 

 margin of the palm is slightly tubercular and rugose ; close to 

 the articulation with the wrist and at the under margin a few 

 oblique, scarcely elevated lines occur on the outer surface of the 

 hand ; a similar line, nearly parallel and close to the under 

 margin, proceeds on the outer surface of the palm as far 

 as the middle of the index. The outer surface of the fingers 

 is perfectly smooth and minutely punctate, when seen under a 

 magnifying-glass ; and they have somewhat excavated horny tips. 



