150 
THE VOYAGE OF H.M.S. CHALLENGER. 
Pilumnus africanus, A. Milne Edwards (PL XIII. fig. 1). 
Pilumnus africanus, A. Milne Edwards, Ann. Soc. Entom. France, ser. 4, vol. vii. p. 280, 1867. 
St. Vincent, Cape Verde Islands, July 1873 (a male and a female of large size, 
with ova). 
The specimens in the Challenger collection agree in nearly all particulars with the 
description of A. Milne Edwards. This species is distinguished from Pilumnus hirtellus, 
of which it may be a variety, by the much more developed spinules of the outer and 
upper surface of the chelipedes, which spinules are arranged, in longitudinal series, and 
from Pilumnus villosus by the unarmed superior margin of the orbit. 
The colour (of specimens dry, and in spirits) is reddish-brown, the pubescence 
yellow ; the spinules of the antero-lateral margins and chelipedes and the fingers are 
black. 
The antero-lateral margins are normally six-spined, but the small spine which 
immediately follows that at the exterior orbital angle (the second of the series) is 
obsolete on one side and very small on the other in the larger (female) specimen. 
dimensions of both are given below : — 
<? • 
Lines. 
Millims. 
Length of carapace, ...... 
5 
10-5 
Breadth of carapace, ...... 
6 
125 
Adult ?. 
Length of carapace, ...... 
13-5 
Breadth of carapace, nearly . 
8 
17 
Pilumnus spinifer (?), Milne Edwards. 
1 Pilumnus spinifer, Milne Edwards, Hist. Nat. Crust., vol. i. p. 420, 1834. 
,, ,, cf. Savigny, Descr. de l’Egypte, Crust. Atlas, pi. v. fig. 4. 
1 „ „ Heller, Crust, des siidliclien Europa, p. 73, 1863. 
OIF Fayal, 50 to 90 fathoms. Several specimens of both sexes. 
The specimens very doubtfully referred to this species are of rather small size, and 
differ from Milne Edwards’ description, but not from the figure cited, in having the 
superior margins of the orbits entire, without spines. The tubercles of the chelipedes 
only tend to become spinuliferous near the superior margins. There are but three 
spines on the antero-lateral margins, exclusive of the small spinule at the exterior angle 
of the orbit, as in the description and figure. 1 
Adult f . Lines. Millims. 
Length of carapace, . . . . . . 4J 9 - 5 
Breadth of carapace, . . . . . . . 5J ll - 5 
1 Dr. C. Heller (Sitzungsb. matli.-nat. Cl. k. Akad. Wiss. Wien, vol. xliii. (i.) p. 345, 1861) at first referred Savigny’s 
Pil/umnus to a new species, designated by Heller Pilumnus savignyi, on account of the non-spinuliferous superior 
margins of the orbits, but in 1863, in the work quoted above, it is referred to Pilumnus spinifer, Milne Edwards. 
