Family SYLVIIDAE. 

 Calamodus aquatica (Gmelin.) l ) — Aquatic Warbler. 



(Plate 59, fig. a-c). 

 (Snouckaert: Avifauna Neerlandica, p. 40, No. 94). 



Colour of surface of shell 

 Colour of spots: 



Average dimensions: 

 Average weight of shell: 

 Texture of shell: 

 Shape : 

 Nest: 



Site of nest: 



Number of eggs: 

 Breeding season: 

 Duration of incubation: 

 Remarks : 



greyish green; greyish yellow; or greyish 

 brown. 



brownish grey; brown. The markings, which 

 are of a cloudy nature, cover the ground 

 colour completely. 



16.9 X 12.7 millimetres. 



0.088 gram. 



not specially characterized. 



ovoidal. 



is constructed of vegetable materials, especi- 

 ally of stems and blades of graminaceous 

 plants, lined with wool (of plants), hair 

 and a few feathers. 



not far from the ground in dense marsh 

 vegetation between stems of cyperaceous, 

 graminaceous and similar plants. 



5-6. 



end of May— June. 



about 13 days. 



It is said of aquatica-eggs that as a rule they 

 are coloured more greenish yellow and 

 usually lighter than those of schoenobaenus. 



Dr. Rey asserts to have been unable to 

 ascertain any constant oological distin- 

 guishing feature for the two species. My 

 own investigation led to the same result. 



They frequently show a great resemblance 

 to eggs of Motacilla flava; the site of the 

 nest, however, excludes their being con- 

 founded with the latter. 



l ) See also for this species the general remarks respecting the Family. 



