214 
THE VOYAGE OF H.M.S. CHALLENGER. 
or more lateral teeth, developed in front of the epibranchial tooth. Postfrontal crest 
extending in an unbroken line from the median incision to the antero-lateral margins. 
Potamonautes, MacLeay. 
The species are mostly African. 
III. Carapace dorsally very convex and dilated in front of the branchial regions, with 
the post-frontal crest and epibranchial tooth obsolete or nearly obsolete. Geothelphusa, 
Stimpson. 
Species mostly Indo-Malaysian, Japanese and Australian. 
Thelphusa nilotica, Milne Edwards, which has a continuous post-frontal crest, and 
the carapace armed with lateral marginal spines behind the epibranchial tooth, should 
perhaps be regarded as the type of a fourth section of the genus. 
The following are species which were inadvertently omitted from the most recent list 
of species of the genus (that published by Mr. Kingsley in 1880) or have been since 
described : — 
Thelphusa borneensis, v. Martens. Borneo. 
Thelphusa dubia, B. Capello. West Africa. 
Thelphusa kuhlii, cle Man. Java. 
Thelphusa limula , Hilgendorf. Senegambia. 
Thelphusa longipes, A. Milne Edwards. Pulo Condore, China Sea. 
Thelphusa madagascariensis, A. Milne Edwards. Madagascar. 
Thelphusa pealiana, Wood-Mason. Assam. 
Thelphusa sumatrensis , Miers. Sumatra. 1 
Thelphusa sinuatifrons (?), Milne Edwards, var. (PI. XVIII. fig. 1). 
Thelphusa sinuatifrons, Milne Edwards, Ann. d. Sci. Nat., ser. 3, Zool. xx. p. 211, 1853 (?). 
„ „ A. Milne Edwards, Nouv. Arcliiv. Mus. Hist. Nat., vol. v. p. 177, pi. x. 
fig. 2, 1869 (?). 
„ „ Miers, Ann. and Mag. Nat. Hist., ser. 5, vol. v. p. 305, 1880. 
Philippines, Mindanao, Pasananca (in the river). An adult male and female are 
referred to this species. 
The female agrees nearly with the description of A. Milne Edwards in the obscurely 
trisinuated frontal margin, and in other characters. 
The male presents a very curious and remarkable variation in the form of the front, 
which I am inclined, however, to regard merely as an individual peculiarity, since it 
differs in no other particulars from the other example from the same locality. The front, 
1 I have quite recently proposed the names Thelphusa cumingii and Thelphusa leichardti, as alternative designations 
for specimens which are allied to but may he distinct from Thelphusa crassa, A. Milne Edwards, and have described a 
new variety ,johnstoni, from Kilimandjaro, Eastern Africa, of Thelphusa depressa, Krauss. 
