IO ORTMANN 



form), in which they have disappeared, is 58 mm. long, but in 

 another, 62 mm. long, they are still recognizable. Three other 

 males of the first form, 69, 71, 72 mm., have no spines. In 

 the females, the spines generally persist up to a size of 60 and 

 62 mm., but they are missing in two females of 62 and 68 mm. 

 length. 



Cambarns pilosimanus is closely allied to C. williamsoni Ort- 

 mann ' from Los Amates, near Izabal, Guatemala. Indeed, it 

 may be identical with it. The difference of the pilosity of the 

 chelse in old individuals of C. pilosimanus is very marked how- 

 ever, but we are to bear in mind that the largest individual of C. 

 •williamsoni was rather small (51.5 mm.). Aside from the pilos- 

 ity of the chelse, the only important difference noted is in the 

 male copulatory organs, C. filosimanus having the shoulder 

 less developed, and the tips of the inner and outer part more 

 strongly contrasted. But this difference is not necessarily spe- 

 cific, since for the rest the copulatory organs of both species are 

 built according to the same plan. Other differences are only 

 slight and apparently unimportant. In the young of C. pilosi- 

 manus, where the pilosity of the chelse is not developed, the car- 

 popodite and meropodite always possess a number of sharp 

 spines, while in C. williamsoni only in the very young are 

 traces of such spines visible on the meropodite. In specimens 

 of about the same size, the granulations of the hand are more 

 distinct in C. williamsoni, although in old individuals of C. 

 filosimanus the granules are much stronger than in any speci- 

 mens of C. williamsoni that are known. Further, the hand of 

 C. pilosimanus is comparativel}' less slender, and is broader 

 than in C. williamsoni. 



The close affinity, if not identity, of these two species is also 

 borne out by the geographical distribution, but the two known 

 localities of C. pilosimanus are farther north than that of C. 

 williamsoni. It is quite possible that additional material will 

 demonstrate their identity, but for the present I separate them, 

 since there is no individual among the material from the prov- 

 ince of Izabal that shows any trace of the pilosity of the chelse. 



1 Ann. Carnegie Mus., Ill, 1905, 439. 



