14 Some Crustacea of Natal 



Alcock, from whom I borrow the first reference, supplies the 

 synonymy down to 1898. Dr. de Man, in 1887, notices a young male 

 specimen as " this very rare species," and gives the measurement of 

 the carapace as 38 mm. broad, 22 mm. long. In our female specimen 

 the measurement is 27 by 16 mm. The surface of the carapace is 

 very much pitted and the sternum still more conspicuously. The 

 pleon attracted attention by two large but unequal tubercles on the 

 last segment. Their unsymmetrical position, however, makes it 

 probable that they are an accidental malformation. The terminal 

 margin, obscured by the tubercles, appears to be trifid, and all the 

 other segments of the pleon are trilobed. The mouth-organs are 

 normal, mandibles strong, first and second maxillipeds weak, especially 

 in comparison with the third pair, in which the third and fourth joints 

 of the endopod and the main joint of the exopod are broad and hard. 

 The chelipeds as preserved are white, and though minutely pitted 

 might be described as smooth ; the confronting edges of the fingers 

 are denticulate. The ambulatory limbs have " both edges of the 

 dactylopodites covered with thick short fur," as described by Alcock 

 for the male. The sharp tips are horn-coloured. 



Locality. The specimen was taken by Mr. A. L. Bevis at Umkomaas. 



Tribe CATOMETOPA. 



In her very important and comprehensive treatise (U.S. Nat. Mus., 

 Bulletin 97, 1918), Miss Rathbun adopts Borradaile's well-known 

 classification, published in 1907, and in introducing "The Grapsoid 

 or Catometopous crabs of America " remarks that " The term 

 Catometopa or 'square-fronted ' was early applied to a group of crabs 

 which was contrasted with the Cyclometopa or ' round-fronted * crabs. 

 These terms were abandoned because the one group was found to 

 merge gradually into the other. The name Brachyhyncha was given 

 to the whole." Further, Miss Rathbun observes that "the so-called 

 Catometopa contain many types that are not ' square-fronted.' " It 

 should, however, be noted that Catometopa does not mean 'square- 

 fronted' but 'down-fronted,' in reference to the bending down of the 

 inter-orbital front. One may reflect that, accepting the principle of 

 evolution, groups will be found obstinately merging one into the 

 other, however you change the names in classification. 



