APPENDICES TO CHAPTER XVIII. 
365 
known. The present case, in which Mantis membranacea from Ceylon, 
Idoleum diabolicum from Kilima-njaro, and Hierodula bioculata from 
West Africa, are infested by a common form, is almost exactly 
paralleled by the case of the Tcenia described by Peters from a 
rhinoceros from the Mozambique, and by Murie and Garrod in 
rhinoceri from India. 
As to the second point which has arisen, the presence of G. verru¬ 
cosus in Central America, I note differences in the form of the integu¬ 
mentary papillae, which are sufficient to induce me to suggest that 
no stress should be at present laid on this point, though they are not 
enough, when taken in conjunction with my own want of experience 
in the degrees of possible variations, to lead me to put myself into 
more decided opposition to the views or determinations of such 
workers as Dr. Baird or Dr. Orley. 
2. Description of a new Variety of River-Crab of the Genus 
Thelphusa , from Kilima-njaro. By E. J. Miers, F.L.S., 
F.Z.S. 
The species of Thelphusa , or River-Crabs, are extremely numerous, 
and their discrimination is often very difficult, on account of the 
changes which the species undergo as they increase in age and size. 
In the collection brought by Mr. H. H. Johnston from Kilima-njaro 
are two specimens of this genus, which I assign, though not without 
some hesitation, to the Thelphusa depressa, Krauss, described from 
types taken near Pietermaritzburg, Natal. They agree with the 
description and figure in their depressed carapace, which is consider¬ 
ably dilated at the branchial regions, in the non-development of the 
lateral epibranchial tooth, and in other essential characters; but 
differ in the more strongly defined cervical suture of the carapace, and 
the more strongly denticulated merus, and much less strongly arcuated 
dactvlus of the chelipedes. As regards this latter character, I may 
observe that in a series of Thelphusce (perhaps T. difor mis ) in the 
Museum collection, the dactyli of the chelipes are in some males 
arcuated, and in others nearly straight. 
I append a detailed description of the specimens from Kilima-njaro, 
which I propose to designate T. depressa , Krauss, var. Johnstoni, but 
which may prove to belong to a distinct species. 
Thelphusa depressa, Krauss, var. Johnstoni. 
Cf. Thelphusa depressa , Krauss, Sudafrik. Crustaceen, p. 38, pi. 11. 
fig. 4 (1843). 
Carapace transverse, widest in its post-frontal region, depressed, 
with the dorsal surface nearly smooth, and divided into two nearly 
