ACAEI OF THE aENUS GLTCIPHAGTJS. 279 



male have a singular assemblage of small, chitinous, recuryed 

 knobs or hooks at their distal ends (fig. 11). 



Abdomen. — This is rounded posteriorly, instead of having a 

 straight hind margin like that of the female. It has ten projec- 

 tions along each side, the same number as the female, but they 

 are larger and differently arranged, as there is greater distance 

 between the first and second, the fact being that vrhat would 

 correspond to the second in the female is rudimentary in the 

 male, the second in the male corresponding to the third in the 

 female. On the other hand, the posterior projections extend 

 not only along the lateral but also along the hind margin, 

 the two tenth projections coming close together in the median 

 line, leaving a deep narrow cut between them ; this is partly due 

 to the fact that the last spine of each dorsal longitudinal row is 

 borne, not on the notogaster, but on a large projecting papilla 

 on the hind margin, which forms the tenth projection of the 

 male, and almost coalesces with the nintb projection. Bearing 

 these differences in mind, so as not to be confused by the 

 numerical order of the projections (i. e. remembering to count 

 the rudimentary second projection), the forms of these projec- 

 tions, the spines they carry, the marginal bands and arching of 

 the notogaster, and the spines upon it, correspond fairly well 

 with the equivalent parts in the female. The copulative organs 

 are placed in the median line between the insertions of the third 

 and fourth pairs of legs. The anus is placed further forward 

 tlifin in the female, and is surrounded by a chitinous band 

 (fig. 5) ; it is protected by two pairs of very large spikes near its 

 posterior margin, the outer pair being the longer. 



The Nymph. 



This is easily known from its similarity to the adult, but there 

 are, of course, numerous differences. In the fully grown nymph 

 the sex is well marked ; the bursa copulatrix and other external 

 sexual organs of the female are easily seen ; so that the male 

 and female nymphs are somewhat different, but not so much so 

 as the adults. Taking the fully-grown female nymph, it will be 

 seen that it is almost white, without the pinkish shade of the 

 adult. The legs are about the size of those of the adult, but the 

 abdomen is considerably smaller and more square in shape ; its 

 edges are more raised and its central part more depressed than 

 the corresponding parts of the adult. The rough projections 



