624 On a neio Clasping-organ in a Centipede. 



from Ecuador, one from Venezuela and Brazil, and one 

 from Brazil. This fact forcibly sugs^ests that other species 

 of the genus, such as P. spiculifer, Poc, from St. Vincent, 

 P. muticus, Karsch, from Peru, &c., will be found to be 

 similarly equipped when further collecting has made them 

 better known. 



A small structural feature not previously noted, I believe, 

 in connexion with these processes is the presence of a small 

 tuft or transverse row of compactly set, short, red bristles, 

 lying backwards lengthwise, near the posterior extremity of 

 the dorsal side (see fig. B). 



The only other genus of Scolopendridae in which similar 

 femoral processes have been described is the remarkable 

 African form Alipes {Eucorybas) . They have been detected 

 in two species, namely, A. appendtculatus, Poc, from Nyasa- 

 land *, and A. calcipes. Cook f, fi'om Quango. In the 

 description of A. appendiculatus I assigned this peculiarity 

 to the male sex, and described as the female of this species an 

 example from the same locality in which the process is repre- 

 sented by a spiniform tubercle. I see no reason to change 

 this opinion. Moreover, since it appears to me to be im- 

 probable that a striking structural feature of this kind is 

 present in some species and absent in others within the limits 

 of the same genus, I am prepared to find that it is character- 

 istic of all the species, and that the numerous specimens seen 

 by myself, Cook, and others in which it is absent are either 

 females or immature males J. However that may be, the 

 development of such an organ in Parotostigmus and Alipes 

 must surely be evidence of affinity between them, especially 

 when it is correlated in both with certain other structural 

 features, such as the unarmed anal femora and pleurae. The 

 view that these genera are related is, moreover, quite in 

 keeping with the faunistic similarities that obtain in other 

 respects between tropical Africa and South America. 



* Ann. & Mas:. Nat. Hist. (6) xviii. p. 95 (1896). 



t ' Brandtia,' xvii. p. 70 (1897). 



X In very Toung examples of Alijjes the posterior legs are almost 

 normal in shape, the distal segments being merely slightly compressed. 

 The modificatiou of these appendages characteristic of the adult is 

 probably gradually acquired during growth, the hual form perhaps being 

 not attained until the final moult. Hence in comparing species with 

 respect to this structure it is necessary that the specimens be certainly 

 adult. According to Cook, these appendages differ considerably in a 

 series of examples from the same locality. Possibly the variations 

 pointed out are explicable in part to diftereuce in age of the specimens 

 examined. 



