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PROCEEDINGS OF THE NATIONAL MUSEUM 



egg strings, but it is apparently more than once; I have often observed 

 developing eggs within the oviducts in females already carrying egg 

 strings. The decrease in proportion of the cephalon in larger (older?) 

 adults may reflect a reduction in their egg-producing organs. Egg 

 strings were present on most individuals in all size groups. 



In order to determine possible host influence on these same charac- 

 ters, adult females of G. watsoni from 4 hosts in the Indian Ocean were 

 examined. These results are as follows: 



Although the average sizes of the adult females of G. watsoni vary 

 depending on the host (shortest on /. orientalis and longest on T. 

 audax), the components seem to remain in about the same proportion 

 and no correlation can be drawn. 



There was no single sample of G. watsoni large enough to permit a 

 meaningful study of a single population. 



The use of the dorsal thoracic plate as a means of separating species 

 has been used by some authors (Wilson 1907, 1919, and Hewitt 1964). 

 There is considerable variation in the shape of this structure and it 

 cannot be relied on as a good taxonomic character (see figs. 43-47). 

 The Atlantic species can be separated from the Indo-Paclfic ones by 

 the angle of inclination at which the outer edges of these plates are 

 held to the anterior-posterior body axis. The Atlantic species have 

 the edges held nearly paraUel whereas the Indo-Pacific ones are at a 

 much greater angle (compare figs. 1, 27, and 38). This character is of 

 no further value in separating species. 



Lewis (1967, p. 63) points out the variation in the postantennal 

 process of G. huttoni (?). I found the same variation in the number 

 of points (3 or 4) on the process (see figs. 4 and 5) in all species. As 

 Lewds also points out, this variation may be present in the same 

 individual (right side differing from left). Twenty-one female 

 specimens of G. watsoni in 3 collection from M. indica in the Indian 

 Ocean were examined. Ten showed 4 points on both sides, 9 had 3 

 on both, and 2 had 3 on one side and 4 on the other. 



Another character selected for study was the 2 rows of stout spines 

 on the dorsal surface of the female genital segment. Typically each 



