690 PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



but very little is, in fact, kncvvii, at present, of their habits and life- 

 histories. 



Marine Crabs. 



(1) V ar una litter ata, F. 



(2) Metaplax dentipes. Heller. 



(3) Sesarma edwardsi, de Man. 



(4) Gelasimus acutus, Stiinpson 



(5) Ampullaria sp., . . . Field-snails. 



1. Varuna litterata, F. 



(Vernacular name Paung-ganan or Paung-si-ganan.) 



According to the reports of the District and Settlement officers, the 

 Varuna crabs come up from the sea with the high tides and enter the 

 paddy fields. They are, at that time, too small to cause any damage 

 to the crop. The young grow in the soil of paddy fields and small 

 creeks and, when full-grown, migrate to the sea for oviposition at the 

 spring tides of the following year. 



The female crab lays her eggs in the sea or on the sea-coast and the 

 young, which hatch out, come up, as already stated, along the creeks 

 and shelter in the fields. 



In the Hanthawaddy district it is said that the yos (blind water 

 courses) and clmungs (streams) are black with them and. while the 

 migration to the stream-banks is going on, cattle cannot go about the 

 fields. 



The adult crabs nip and eat up the sprouts ; hence the sowing is 

 delayed and carried on only after they quit the fields and before the 

 young come up from the sea. It is not practicable after the invasion 

 of the young, as the fields stink badly from their presence. 



It is said that the whole field, where young plants have just sprouted, 

 is destroyed in a single night. It is usual to ascertain whether the adult 

 crabs have departed or not by scattering a few handfuls of seed in the 

 flooded fields. Should this come up, sowing is continued ; if it does 

 not, fresh experiments are made. 



Personal Inquirij and Observation. 

 The adult crabs go down to the sea, as stated above, with the spring 

 tides in July and August for oviposition, and the young, which hatch 

 out, come up with the high tides in September and October in such 

 great masses that they cover the banks of the creeks which look white 

 whilst they remain there, for a day or two if the water is low. They 

 are carried up into the fields over very extensive areas with the tidal 

 water. The tidal water remains on the fields for two or three hours 



