some Species o/P;ilamnf\3US. 41 



For in tlic former tlie tail is more tlian three and a half times 

 the length of the cephalothorax, while in the latter it is less. 

 This circumstance strengthens the evidence of identity 

 between P. spimfer and P. Petersii ; for the figure of P. 

 spinifer shows that the tail (judging from the sketch of the 

 lateral view of it) is a little over three and a half times the 

 length of tlie cephalothorax. 



Mons. Simon has recorded a species which he considers to 

 be Petersii ixom. Bintang. The males of iiis specimens, how- 

 ever, are not like those that I here call spinifer^ inasmuch as 

 they are declared to be like lonpimanus, Ilerbst. This opens 

 the interesting question of possible dimorphism in the males. 

 !Now three male examples have been described without 

 their females being known. These are hngimanus of Herbst, 

 hngimanus of C. Koch (which is not the same specimen at 

 least as Herbst's type), and ancjustimanus oi Thorell. I give 

 a table to show the dimensions of these specimens, together 

 with those of two examples in the British Museum which I 

 provisionally refer to angustimamis. A glance shows that 

 the two examples named longimanus have the hand-back very 

 short and the movable dactylus long, the difference between 

 the two being 7'5 and 8 millim. respectively, whereas in the 

 others the difference is '5, 2, and 2*5 millim. But this great 

 interval is almost entirely bridged over by some of the male 

 specimens of spinifer. Thus in no. 5 the difference in length 

 between the dactylus and the hand-back is 3, in no. 1 it is 

 3*5, in nos. 2 and 6 it is 4, in no. 4 it is 4'5, and in no. 3 it is 

 6 — the amount of variation being considerable. 



I am consequently disposed to think that at least longi- 

 manus of C. Koch may be a form of the male of spinifer^ and 

 I hold the same opinion with regard to the two males in this 

 collection that I have named angustimanus. P. costimanus of 

 C. Koch is also, I think, probably synonymous with spinifer. 

 It is worthy of note in connexion with this subject that the 

 slenderness of the hand appears to be correlated with the 

 longitudinal wrinkling of the upper surface. Consequently 

 the presence of strong cost« on the hands of these males that 

 have just been discussed need not point to specific distinction 

 between them and spinifer^ in which the costse are less 

 manifest. 



