BEAUTIFUL COLOURING 12% 
Stimpson, and Actceomorpha, Miers, are distinguished from 
Matuta by having the terminal joints of the legs adapted, 
not for swimming, but for walking. Osachila and Actco- 
morpha are, according to the author of tLe latter genus, 
perhaps identical. 
Family 3.—Leucosude. 
The afferent channels to the branchiz open at the 
antero-lateral angles of the endostome and not behind the 
pterygostomian regions. The third maxillipeds have the 
three terminal joints wholly concealed by the triangular 
fourth joint. The verges of the male are exserted from 
the sternal plastron. 
In this family twenty-nine genera are accepted by 
Miers.in 1886. One of them is included in the fauna of 
Great Britain. | 
Leucosia, Fabricius, 1798, contains numerous species, 
which occur in the littoral and shallow waters of the Indo- 
Pacific region. They are often remarkable for the beauty 
of their colouring, testimony to which is borne in the 
names of the species, Leucosia splendida, Haswell, and 
Leucosia pulcherrima, Miers. They have the frontal re- 
gion of the carapace narrowed and produced anteriorly, 
and in front of and above the bases of the chelipeds there 
is a pit defined by a series of granules. This, which is 
continued as a shallow excavation beneath the postero- 
lateral margins of the carapace, has received the name of 
the thoracic sinus. The walking-legs are small, succes- 
sively shorter from the front to the rear. The pleon of 
the male in some species has all the segments united ex- 
cept the first and last, in others the third coalesced with 
the fourth, and the fifth with the sixth. A figure of 
Leucosia australiensis, Miers, is given on Plate Il. The 
type species, scabriuscula, Fabricius, has been transferred 
to the next genus. 
Philijra, Leach, 1817, is a genus nearly allied to Leu- 
cosia, With a similar range, and also containing several 
species. But, among other distinctions, the ‘front’ is 
