Mr. E. J. Miers on the Plagusiine. 147 
abdomen 20; length of tegmina 56, breadth of tegmina 23, of 
their marginal area 8; length of stigma 3°75; of fore coxa 
21:5, femur 24°3; of intermediate femur 21, tibia 18; of pos- 
terior femur 25, tibia 25. 
Dried specimen. 
Hab. Ceylon. Communicated by Mr. F. M. Mackwood, of 
Colombo. 
6. Mierodula trimacula. 
Hierodula trimacula, Saussure, Mélanges Orthopt. i. 3° fase. p. 82, 
pl. v. fig. 29, 9. 
Hab. Oman, Arabia, obtained by Colonel Miles, the British 
Resident at that place. The species was described from a 
specimen in the Paris Museum, marked ‘‘ China ?”’ 

XVI.— Revision of the Plagusiine. By Epwarp J. Miers, 
F.L.S., F.Z.S., Assistant in the Zoological Department, 
British Museum. 
TuHE following is a synonymic list, with brief diagnoses and 
remarks, of the species of this small and well-defined group, 
which belongs to the subtribe Catometopa, or Grapsoid Bra- 
chyura, and is peculiar on account of the remarkably flattened 
carapace and of the position of the antennules, which are 
exposed in deep longitudinal clefts or sinuses of the front 
and are visible in a dorsal view. It contains but two genera, 
Plagusia and Leiolophus*. 
In determining and naming the species in the collection of 
the British Museum, I found that several of those recorded 
had apparently been established on insufficient grounds, and 
that of others the commonly received designations could not 
be retained ; and I think it will be useful to place these obser- 
vations on record, and at the same time indicate those cha- 
racters which I have found most constant and reliable for 
distinguishing the species. 
* The curious genus Crossotonotus, recently established by M. A. 
Milne-Edwards (Nouv. Archiv. Mus. Hist. Nat. ix. p. 282, 1873) for a 
species (C. compressipes) from the Samoa Islands and New Caledonia, 
presents many affinities with the Plagusiinee, but cannot be referred to 
this group, on account of the absence of the frontal sinuses. The genus 
Plagusetes, based on a species from Chili (P. elatus), described by Heller in 
the preliminary synopsis of the Crustacea of the ‘ Novara’ Voyage (Verh. 
zool.-bot. Gesell. Wien, xii. p. 522, 1862), is not mentioned in his final 
report, but seems to have been based on specimens subsequently referred 
to Acanthocyclus Gayi, a genus belonging to the Cancroidea, but possessing 
some affinities with the Plagusiine. 
