34 G. O.'SARS. [SEC. ARC. EXP. FRAM 



legs smaller than in female, with the inner expansion of proximal joint 

 much shorter and provided with only 3 spiniform setae. 



Length of adult female 1.08 mm. 



Remarks. The above-described form is unquestionably iden- 

 tical with the species recorded by Prof. LILLJEBORG under the above 

 name from Siberia. It is about the same size as the type species, 

 C. staphylinus (JURINE), which it also resembles in the general form of 

 the body, though at once distinguished from it by the very different shape 

 of the caudal rami and by the perfectly smooth anal opercle. Like all 

 true Canthocampti, it is a genuine fresh-water form. 



Occurrence. Some specimens of this form occurred in a 

 sample taken on June 26, 1899, from some fresh-water pools (the exact 

 locality not indicated). 



Distribution. Northern part of Siberia, at Sopotschaja Korga 

 near the mouth of the Jenisei, and on the peninsula Jalmal (LILLJEBORG). 



117. Ameira longipes, BOECK. 

 Found rather abundantly in 6 different bottles. 



118. Ameira tau (GIESBRECHT). 



Some few specimen of this small species occurred together with the 

 preceding form in one of the bottles. 



119. Parameira elongata, G. 0. SARS, n. sp. 



(PI. X). 



Specific Characters. Female. Body very slender and 

 elongated, sub-cylindric in form, with the anterior division scarcely 

 broader than the posterior. Cephalic segment about the length of the 

 3 succeeding segments combined; rostral projection almost obsolete. 

 Urosome fully as long as the anterior division, and having the segments 

 apparently perfectly smooth; last segment larger than the preceding one, 

 and deeply incised behind. Caudal rami rather far apart and somewhat 

 produced, being almost twice as long as they are broad; middle apical 

 setae rather slender and elongated. Anterior antennae of moderate lenglh 

 and densely clothed with slender setae, 8-articulate, terminal part exceed- 

 ing half the length of the proximal one, and having the penultimate 

 joint imperfectly divided in the middle. Posterior antennae and oral 

 parts exhibiting the structure characteristic of the genus. 1st pair of 

 legs with the rami very unequal, the outer one extending to about the 



