112 
THE VOYAGE OF H.M.S. CHALLENGER. 
well as the orbital margins, may, however, be interrupted by very minute notches or 
fissures ; the lobe at the exterior orbital angle, and ordinarily the lateral epibranchial 
lobe, are not developed. The post-abdomen in the male is usually five-jointed, with the 
third and fourth, and the fifth and sixth segments coalescent. The basal joint of the 
antennae is shorter and attains the inf ero -lateral process of the front, but is not prolonged 
within the orbital hiatus. The merus of the exterior maxillipedes is much less obliquely 
truncated at the distal extremity. The chelipedes of the adult males are less massive, 
and usually subequal. The fourth to the sixth joints of the ambulatory legs are not merely 
compressed, but somewhat dilafed, and carinated. 
The species are rather numerous and occur throughout the Indo-Pacific region, in 
shallow water and on the shore. The sole representative of this genus in the Challenger 
collection is the Atergatis jloridus of Linne, which is the longest known, commonest, 
and most widely distributed member of the genus. 
To the species enumerated by A. Milne Edwards, I may add the following : — 
Atergatis asperimanus, White = Atergatis insularis, Adams and White. 
Philippines . 1 
Atergatis montrouzieri, A. Milne Edwards. New Caledonia. This species is 
perhaps identical with Atergatis asperimanus. 
Atergatis roseus, var. alba (sic.), Kossmann. Red Sea. 
This author regards Atergatis marginatus, de Haan, Atergatis scrobiculatus, Heller, 
Atergatis Isevigatus, A. Milne Edwards, and Atergatis nitidus, A. Milne Edwards, as 
mere varieties of Atergatis roseus. 
v 1 
Atergatis Jloridus (Linne). 
Cancer Jloridus, Linn., Syst. Nat., ed. 12, p. 1041, 1766. 
Cancer scyrde, Herbst, Naturgesch. der Krabben u. Krebse, vol. iii. p. 20, pi. liv. fig. 2, 1801. 
„ „ Milne Edwards, Hist. Nat. Crust., vol. i. p. 375, 1834. 
Atergatis Jloridus, de Haan, Crust, in Siebold, Fauna Japonica, pp. 17, 46, 1835. 
„ ,, Dana, Crust, in U.S. Expl. Exped., vol. xiii. p. 159, pi. vii. fig. 4, 1852. 
I Atergatis compressipes, MacLeay, Annulosa, in Smith, Zool. S. Africa, p. 59, 1849. 
Ternate (an adult male and female) ; Zebu, on the reef (an adult male). 
Adult J . 
Lines. 
Millims. 
Length of carapace, nearly 
14 
29-5 
Breadth of carapace, .... 
20 
42 
1 In the lobulated dorsal surface of the carapace this species approaches Lophozozymus, but as the antero- lateral 
margins are entire, I refer it to Atergatis. It has been considered by A. Milne Edwards to be synonymous with i 
Lophozozymus radiatus, Milne Edwards, hut it differs from Milne Edwards’ description of Lophozozymus radiatus both as j 
regards the antero-lateral margins and the chelipedes. In the Ann. and Mag. Nat. Hist. ser. 5, vol. viii. p. 204, | 
1881, I erroneously referred to Atergatis lateralis, White, as being regarded by A. Milne Edwards as synonymous with 
Lophozozymus radiatus. 
i 
