REPORT ON THE BRACHYURA. 
123 
Atergatopsis, A. Milne Edwards. 
Atergatopsis, A. Milne Edwards, Nouv. Archiv. Mus. Hist. Nat., vol. i. p. 252, 1865. 
Carapace transverse, regularly convex, with the dorsal surface smooth or granulated, 
but not distinctly lobulated as in Actsea. The front (in the adult) is less than one-third 
the width of the carapace, its anterior margin is sinuated or indistinctly quadrilobated ; 
the antero-lateral margins of the carapace are longer than the postero-lateral margins, 
regularly arcuated, neither cristatecl as in Atergatis, nor as distinctly lobated as in Actsea. 
The post-abdomen in the male is usually five-jointed, with the third to the fifth segments 
coalescent. The orbits, eyes, antennas, and exterior maxillipedes are nearly as in Actsea ; 
the basal antennal joint reaches the infero-lateral process of the front. The chelipedes, 
in the adult male, are subequal and well developed, with the carpus bluntly toothed or 
lobed on the inner margin ; palm rounded, not cristatecl above ; fingers lobecl or toothed 
on the inner margin, and acute at the distal extremity. The ambulatory legs are of 
moderate length, with the fourth to the sixth joints usually somewhat compressed, but 
not greatly dilated or carinated ; clactyli slender and nearly straight. 
From Actsea this genus is distinguished by the more convex and less distinctly 
lobulated carapace, with sub-entire, antero-lateral margins, and from Atergatis by the 
non-carinated and non-cristated antero-lateral margins of the carapace, and joints of 
the ambulatory legs. 
The species, which may attain a considerable size, occur throughout the Indo-Pacific 
region. The following species has been described since the publication of A. Milne 
Edwards’ monograph of the genus : — 
Atergatopsis amoyensis, cle Haan. China, Amoy. 
Atergatopsis granulatus, A. Milne Edwards. 
Atergatopsis granulatus, A. Milne Edwards, Nouv. Archiv. Mus. Hist. Nat., vol. i. p. 255, 
pi. xiii. fig. 2, 1865. 
„ „ Miers, Crust, in Rep. Zool. Coll. H.M.S. “Alert,” p. 529, 1884. 
South of New Guinea, 28 fathoms, lat. 9° 59' 0" S., long. 139° 42' 0" E. (Station 
188), a very small female. 
In this specimen the carapace is granulated only near the front and antero-lateral 
margins ; the chelipedes are granulated as in the adult. The cervical and other sutures 
of the dorsal surface of the carapace are scarcely distinguishable. The strong compressed 
tooth of the lower (immobile) finger or pollex is distinctly developed. 
$ . Lines. Millims. 
Length of carapace, about ...... 3| 7 
Breadth of carapace, nearly . . . . . . 5 10 
