REVISION OF SIMOCEPHALUS DAPHNIIDAE 


Fig.8 S. verulus. A, 1st limb of female, B, hook of endopod of Ist limb of adult male, C, Ist limb of male, D, hook of endopod of Ist limb of juvenile male. 
DISTRIBUTION. (Fig. 21) Europe, North Africa. This species was 
previously assumed to be cosmopolitan (Manujlova, 1964). But the 
investigation of specimens from different regions shows, that S. 
vetulus occurs in Europe and North Africa only. In other regions it is 
replaced by closely related species: S. mixtus, S. vetuloides, S. 
gibbosus, S. elizabethae and S. punctatus. 
REMARKS. The original description of S. vetulus is very short: 
“Daphne Vetula cauda inflexa, testa mutica’ (Miiller, 1776). This is 
appropriate for any species of Simocephalus. Later, Miiller (1785) 
renamed this species Daphnia sima. The name ‘vetulus’ is not 
grammatically correct (Dumont, 1977). ‘Vetula’ means ‘an old 
women. This is not an adjective, but a substantive. Its gender cannot 
alter. However, it is not necessary to change the name ‘S. vetulus’, 
because it has come into common use. 
Some authors in the 19th century (Lievin, 1848; Baird, 1850; 
Leydig, 1860) supposed S. exspinosus and S. congener to be syno- 
nyms of S. vetulus. According to recent data, S. vetulus differs very 
much from these species and even belongs to another subgenus. 
According to Jurine (1820), S. nasutus (Monoculus nasutus 
