64 
THE VOYAGE OF H.M.S. CHALLENGER. 
Measurements. 
In inches and 
decimals. 
In thousandths 
of total length. 
Total length of female specimen from Samboangan Reefs, 
Measurements on middle line : — 
2-05 
Rostrum, ........ 
T7 
83 
Carapace, ........ 
•51 
249 
Carapace, including rostrum, ..... 
•68 
332 
From posterior edge of carapace to posterior edge of third thoracic 
somite, ........ 
From posterior edge of third to posterior edge of fourth thoracic 
•10 
49 
somite, ........ 
From posterior edge of fourth to posterior edge of fifth thoracic 
•10 
49 
somite, ........ 
First abdominal somite, ...... 
•10 
49 
•12 
59 
Second abdominal somite, ...... 
13 
63 
Third abdominal somite, ...... 
T3 
63 
Fourth abdominal somite, ...... 
•13 
63 
Fifth abdominal somite, ...... 
T8 
88 
Sixth abdominal somite, ...... 
•16 
78 
Telson on middle line, ...... 
•22 
107 
Total length of hind body, ..... 
1-37 
668 
Total length on middle line, .... 
2'05 
1000 
Greatest length of telson, ...... 
•30 
146 
Width of rostrum, ....... 
•15 
73 
Width of carapace at antero-lateral angles, .... 
•25 
122 
Width of carapace (greatest), ...... 
•35 
171 
Width of third thoracic somite, ..... 
•39 
190 
Width of fourth thoracic somite, ..... 
•39 
190 
Width of fifth thoracic somite, ..... 
•39 
190 
Width of first abdominal somite, ..... 
•39 
190 
Width of second abdominal somite, ..... 
•39 
190 
Width of third abdominal somite, ..... 
•39 
190 
Width of fourth abdominal somite, ..... 
•39 
190 
Width of fifth abdominal somite, ..... 
Width of sixth abdominal somite between postero-lateral spines, 
•39 
190 
•32 
156 
Width of telson between submedian spines, .... 
•08 
39 
Width of telson between intermediate spines, 
•22 
107 
Width of telson (greatest), ...... 
•31 
151 
Length of paddle of exopodite of uropod on dorsal surface, 
•12 
58 
Length of second joint of exopodite of uropod on dorsal surface, 
•28 
137 
prominence, which is more protuberant both in Gonodactylus glabrous and in Gono- 
dactylus graphurus than it is in Gonodactylus chiragra. 
The very close resemblance between the three species shows their close relationship, 
and it is quite possible that future discoveries may reveal so many transitional forms 
that the sharp lines between the species will break down, but in the present state of our 
knowledge of the group I think we are compelled to recognise the three as distinct 
species. 
