REPORT ON THE BRACHYURA. 
89 
These specimens agree with Milne Edwards’ description and figure in all particulars, 
except in having the ridges of the branchial regions somewhat more prominent and 
defined by deeper intervening depressions ; there are obscure indications of a transverse 
series of five tubercles upon the front of the gastric region in the smaller specimen (that 
from Bahia) which do not exist in the larger specimen and in the figure of Milne 
Edwards. 
The dimensions of the specimen from Bermuda are as follows : — 
Adult ?. 
Lines. 
Millims. 
Length of carapace and rostrum, ..... 
14 
Breadth of carapace, nearly ...... 
n 
15 '5 
Length of a chelipede, ...... 
H 
20 
Length of first ambulatory leg, ..... 
H 
20 
Several small and not nearly fully grown Mithraculi are in the 
Challenger collection 
from Fernando Noronha, 7 to 20 fathoms, which may belong to this or to a distinct 
species ; they differ in having the dorsal surface of the carapace much less distinctly 
tuberculated, and in possessing more slender ambulatory legs. In the largest the carapace 
is not 3 lines in length (6 mm.). 
Mithrax coronatus (Herbst). 
Cancer)' coronatus, Herbst, Naturgesch. der Krabben u. Krebse, vol. i. p. 184, pi. xi. fig. 63, 
1790. 
Cancer coryplie, Herbst, tom. cit., p. 8, pi. iii. 1801. 
Mitliraculus coronatus, White (part), List Crust. Brit. Mus., p. 7, 1847. 
„ „ A. Milne Edwards, Crust, in Miss. Sci. au Mexique, pt. 5, p. 106, pi. xx. 
fig. 1, 1875, and references to literature. 
A very small male and female collected at Fernando Noronha, in 7 to 20 fathoms, are 
referred to this species, as distinguished and figured by A. Milne Edwards. 
<J. 
Lines. 
Millims. 
Length of carapace, nearly .... 
3 
6 
Breadth, nearly ..... 
34 
7 
Length of a chelipede, .... 
3| 
7-5 
Length of first ambulatory leg, nearly . 
4 
8 
Mithrax sp. (PI. X. fig. 3). 
To render the account of the Challenger specimens of this genus complete, I subjoin a 
description of a specimen which I cannot refer to any species of the genus, but to which 
I do not apply any specific name, as it is of extremely small size, and the characters are 
probably not those of the fully grown individual. 
(ZOOL. CHALL. EXP. — PART XLIX. — 1886.) 
Ccc 12 
