230 A HISTORY OF RECENT CRUSTACEA 
varieties of one great type. In Glyphocrangon aculeatus, 
A. Milne-Edwards, the carapace is ornamented with eight 
carine, but in Glyphocrangon granulosus, Spence Bate, 
there are five on each side of the median line, besides a 
small central one on the rostrum. The telson in this 
genus is described as a long bayonet-shaped organ, which 
the animal during life has the power of locking in a fixed 
position, so as to render it a very powerful weapon of 
offence, and of again unlocking at its own will. When 
fixed for striking it is supported in position by having a 
strong cusp or tubercle on its dorsal surface brought into 
contact with a curved process of the preceding segment. 
Glyphocrangon rimapes, Spence Bate, was trawled in the 
South Atlantic from a depth of 1,715 fathoms, and it is 
noted as an instructive coincidence that in Willemocsia 
leptodactyla, obtained in the same haul, the organs of 
vision are reduced to a rudimentary condition, while in 
Glyphoecrangon they are unusually large. 
Nikoides, Paulson, 1875, is distinguished from Nika by 
having an exopod on the first pair of feet, and by subdi- 
vision of the fourth joint as well as of the fifth in the 
second pair. The type Nikoides Dane is from the Red Sea. 
Family 2.-—Alpheide. 
The rostrum is minute or of moderate size; the eye- 
stalks are short,and more or less covered by the projection 
of the frontal margin of the carapace ; the mandibles have 
a cutting edge distinct from the molar process, and a one- 
or two-jointed ‘ palp;’ the first pair of trunk-legs are 
robustly chelate, sometimes unsymmetrical, the second pair 
are long and slender, minutely chelate. | 
Spence Bate makes a two-jointed mandibular ‘ palp ’ 
a character of the family, but in describing his own genus 
Paralpheus, he says that it is uniarticulate, and in Alpheus, 
Fabricius, ‘ three-jointed, the Jatter being probably a slip 
of the pen for two-jointed. Ten or more genera have 
been assigned to the family, two of which occur on the 
coasts of Great Britain. 
Alpheus, Fabricins, 1778, has a short poimted rostrum, 
