Genua Grabhamia. 



293 



particular as to their pools, partly due, no doubt, to the presence 

 of natural enemies. They are not to be found in pools where 

 fiddler-crabs run ; wherever high tides cover frequently ; wherever 

 fish are carried in with the tide, and the solid, flat areas where 

 water drains off completely in a day or so after the flooding. 

 The favourite places are marsh-land broken up by little holes 

 and pools, old ditches grass-grown at the mouth, and stretches 

 left at the sides of roads and railways. The smaller, shallow, 



Fig. 98. 



Grabhamia sollicitans. Walker. 



a, Labial plate ; b, antenna ; c, apical segments and siphon 

 d, scale of comb ; e, scale of siphon pecten (after Smith). 



grassy ponds which are often dry are the most prolific breeding 

 grounds. 



As a rule the aquatic stages prefer clear water, but they may 

 be found in foul and fermenting pools. 



The larva is dirty-grey in colour, often with a whitish hue ; 

 the head is yellow with or without markings; siphon short, 

 stout, and brown ; antennae short with a small lateral tuft of 

 four rather long bristles ; anal gills short. 



There are two rows of toothed spines on the siphon, from 

 16 to 24 in each row. The spines have from 1 to 5 teeth and 

 may be slender or stout. 



Scales of eighth segment from 20 to 40 in number ; each scale 

 has an acute end and small lateral spines, seven in number. 



Length. — 8 to 9*4 mm. 



