Account of the Crustacea and the Pycnogonida. 77 



? Diaptomus silicis var. imperfectus Forbes, On some Lake Superior 



Entomostraca; Report U. S. Comm. Fish and 



Fisheries, 1887, p. 703 (teste Marsh 1. с 1897, 



p. 8, and Giesbrecht u. Schmeil 1. с 1898), 



The above hst contains everything I have been able to find in hte- 



rature about this species with the exception of a short note by Guerne 



& Richard in Compt. Rend., 1889 (Sur la faune des eaux douces du 



Groenland) where it is just mentioned that it has been taken in some 



places in Greenland. 



In the following I shall give a short list of the contents of the papers 

 cited, especially of the figures. 

 Lilljeborg, 1889: Description; p. 5, S (PL 1, fig. 5); p. 5, ? (fig. 6); apex of 



right antenna, ,$ (fig. 14); abdomen ? (PI, 3, fig. 25). 

 Marsh, 1891: Short note. 



— 1893: Short note; p. 5, ^ (PI. 4, fig. 1); p. 5, ? (fig. 2); apex of 

 right antenna 1, S (fig. 3). 



— 1897: Short note; p. 5, c? (PL 7, fig. 3, taken from Marsh, 1893, 

 PL 4, fig, 1); p. 5, ? (fig. 4), 



Herrich &: Turner, 1895: I have not had access to this paper, 

 Schacht, 1897: Reproduction of Lilljeborg's description and copies of 



his figures, 

 Giesbrecht u. Schmeil, 1898: Description. 



Marsh, 1907: Description; p. 5, $ (PL 17, fig. 7); apex of right antenna 

 1, 6 (fig. 11); abdomen ? (PL 18, fig. 1); p. 5, ^ (PL 18, fig, 7). 



As may be seen, it is nearly always the same limbs which are figured. 

 Diaptomus silicis var, imperfectus Forbes is regarded by Marsh (1, с 

 1897) and Giesbrecht u. Schmeil, 1898, as a synonym of this species 

 (the two last, however, with a?); but Schacht (1. с. 1897, p. 158) says 

 that this form is probably not synonymous with D. minutus, but with 

 D. ashlandi Marsh, 



Consequently, as there are no figures of the entire animal I have 

 given in PL 7 — 8 figures of the entire animal and drawings of all the 

 limbs. On the whole my specimens agree excellently with the descriptions 

 of Lilljeborg (1889) and Marsh (1907); but I have not been able to 

 find the small spine on either side of the genital segment of the $, 



. Lilljeborg mentions that the ? has only two eggs, but Marsh says, 

 that six is the usual number. Almost all my specimens have six eggs, 

 lying in one plane, as seen in the figure in dorsal view; in the figure of a 

 $ seen from the. side, they have been pressed into another position by 

 the cover-glass. 



Several $ specimens had a long spermatophore; a single of these 

 specimens was however abnormal as the genital segment was divided 

 into two (see Fig, on PL 7 ? Uros. abn.). 



In the other cases it will suffice for me to refer to my figures. 



