REPORT ON THE BRACHYURA. 
245 
are often deficient, the subdistal triangulate tooth of the pollex or lower finger being that 
most permanent and characteristic of the species . 1 
Gonoplacinse. 
Gonoplcix, Leach. 
Gonnplax, Leach, Trans. Linn. Soc. Lond., vol. xi. p. 323, 1815. 
„ Milne Edwards, Hist. Nat. Crust., vol. ii. p. 60, 1837 ; Ann. d. Sci. Nat, Zool., vol. xviii. 
p. 162, 1852. 
Carapace transverse, longitudinally rather convex, dorsally smooth, with the antero- 
lateral angles terminating in spines, which are not greatly produced, as in Ommatocar- 
cinus. The front is deflexed, and rather less than one-third of the width of the carapace, 
and its anterior margin is straight ; the orbits are well defined, and extend along the 
whole anterior margin of the body between the front and antero-lateral angles. The 
epistoma is transverse ; the ridges of the endostome or palate are nearly obsolete ; the 
post-abdomen in the male is rather broad, distinctly seven-jointed, and at the base covers 
the whole width of the sternum. The eye-peduncles are elongated. The antennules are 
transversely plicated. The basal antennal joint is small, and does not reach the infero- 
lateral process of the front, and the flagellum is somewhat elongated. The exterior 
maxillipedes present nothing remarkable; their ischium-joints are longitudinally sulcated, 
and are not produced at the antero-internal angles ; the merus-joints are distally trun- 
cated, the antero-external angles not produced, and the antero-internal angles, where the 
next joint articulates, usually slightly emarginated. The chelipedes in the adult male 
are subequal and very considerably elongated ; the merus-joints subcylindrical, and often 
exceeding in length the width of the carapace ; carpus short, without a spine on the 
interior surface ; palm about as long as the merus and compressed, fingers rather 
robust and compressed, dentated or tuberculated on the inner margins, and distally 
acute. The ambulatory legs are moderately elongated and slender, with the dactyli 
styliform. 
To the long known European and North Atlantic species of this genus is to be added 
an apparently new form, which I propose to designate Gonoplax sinuatifrons. 
1 I have thought it useful to give the leading references to the synonyma of this species, so far as I am acquainted 
with them, since Mr. Kingsley’s are incorrect in some particulars, or incomplete. Thus the West American Gelasimus 
macrodactylus, Milne Edwards and Lucas, cannot, in my opinion, be regarded as synonymous with Gelasimus a7inulipes, 
but, as the description and figure and specimens in the British (Natural History) Museum show, is a species with much 
more convex carapace and less prominent antero-lateral angles, and with differently shaped chelipedes and fingers. 
Gelasimus perplexus is stated by Hilgendorf to be synonymous, not with Gelasimus chlorophthalmus, Milne Edwards, as 
stated by Kingsley, but with Gelasimus annulipes. Gelasimus gaimardi, Milne Edwards, may also possibly be a variety 
of this species, but specimens referred to it in the British Museum collection may be distinguished by the rounder 
front and more tapering and slender dactylus of the larger chelipede, while the palm has a cicatrice on its outer surface. 
Gelasimus pulchellus, Stimpson, from Tahiti, is, to judge from the short diagnosis, a species or variety intermediate 
between Gelasimus annulipes and Gelasimus gaimardi. 
