156 RICHAED EVANS. 



name, Demeraranus, though Mr. Sclater had previously 

 given the same specimens (in part, at least) the name im- 

 Thurmi.^ If Mr. Sedgwick had followed a middle course, 

 and had arrived at the conclusion that he had two species 

 among the fourteen specimens which he examined, it would 

 seem that he would have been nearer the truth than he was 

 in the supposition that he might have three, or in the con- 

 clusion which he adopted, that he had only one. This view 

 is supported by the following facts : — In the first place, out 

 of the specimens possessing thirty or thirty-one pairs of 

 appendages, Mr. Sedgwick obtained embryos with either 

 thirty or thirty-one pairs, but out of the one with twenty- 

 seven pairs he took embryos with either twenty-seven or 

 twenty-eight pairs. In the second place, Mr. Sedgwick 

 counted the number of appendages in no less than thirty-one 

 specimens, both embryos and adults, and yet not a single 

 specimen was found possessing twenty-nine pairs, which is a 

 very curious fact if all the specimens belonged to one species. 

 In the third place, all the fourteen specimens examined by 

 Mr. Sedgwick were females, and consequently not likely to 

 belong to one species. If the specimen with twenty-seven 

 pairs of appendages had been a male, Mr. Sedgwick's view 

 that he had only one species would not have been so im- 

 probable, as the males often have fewer appendages than the 

 females. It may be fairly concluded that Mr. Sedgwick had 

 among his fourteen specimens the representatives of two 

 species ; and, further, it is possible that if he had been writing 

 his monograph to-day, instead of twenty years ago, he would 

 have adopted a different view. 



M. Bouvier,^ in his review of the American Peripatida3, 

 does not raise the question here considered, and adopts Mr. 

 Sclater's name (im-Tliurmi) in preference to that of Mr. 

 Sedgwick (Demeraranus). 



' "On tlie Early Stages of the Development, of a South Ameiiran Species 

 of Peripatus," 'Quart. Journ. Micr. Sci.,' vol. xxviii, pp. 343 — 361, 

 pi. U. 



* 'Ann. de la Soo. Eutoiuol. do France,' vol. Ixviii, 1899, pis. li— vii. 



