iRT. 18 SYNOPSIS OF CALANOID CRUSTACEA MABSH 5 



Birge and Juday (1914) found it in Cayuga, Seneca, Canandaigua, 

 Skaneateles, and Owasco Lakes in New York. Bajkov (1930) 

 reported it from Lake Winnipeg. Stephensen (1913) and Haber- 

 bosch (1916) reported it from Greenland. 



The description of this species and of the genus is largely from 

 the original account by Sars, but modified somewhat by the results 

 of later investigations. The enlarged head and cervical depression 

 are certainly not so marked in American material as is indicated by 

 the figures by Sars, but this peculiarity is less marked in Nordquist's 

 drawings. In Plate 1, Figure 2, it is much less marked than in 

 Figure 3. 



There is some lack of agreement in regard to the number of seg- 

 ments in the exopod of the second antenna. This was discussed by 

 Schacht (1898), and he is correct in considering the exopod as 

 7-segmented, not only in L. inacrurus but in the genus; it is evi- 

 dent that the lack of agreement is due to the indistinctness with 

 v.hich the separation of the middle segments is marked. 



Remarks. — L. macrwi^s is generally considered as belonging to 

 rhe fauna relicta; that is, it is a salt-water form that has gradually 

 become adapted to a fresh-water environment. Generally speak- 

 ing, it is found only in fairly deep lakes and most abundantly at 

 considerable depths. Its habits with relation to temperature and 

 light are discussed by Marsh, 1897 (pp. 200-202). Rylov (1922 and 

 1930) lists this species as Z. grimaldii var. macrurus. As there is no 

 available translation of his Russian text, I can not state why he has 

 made this change. 



LIMNOCALANUS GRIMALDII (de Guerne) 



Plate 1. Figures 4, 6, 7 



Centropages grimaldii de Gtjerke, 1886, pp. 276-285. 



Umn-ocalanus macrurus Nordqtost, 1888, p. 31. — de Gukrne and Riciiakd, 1889, 



pp. 77, 78.— Schacht, 1898, p. 243. 

 Lminocalanus grimaldii Saks, 1897, pp. 39-49, pi. 4. figs. 1-lS ; 1898, p. 12, pi. 8, 



fig. 7.— WiLLET, 1920, p. UK.— Pesta. 1928, p. 27, fig. 19, w-c— Ryi^v, 1930, 



pp. 63, 64, fig. 13, 1 and 2, fig. 14, 1 and 2. 



L. grirrialdii differs from L. onacruims in the characters given in 

 the key, that is, in the flat head with no cervical depression, in the 

 pointed sides of the last cephalothoracic segment, and in the greater 

 length of the female antennae. While the number of segments in 

 the terminal portion of the right antenna of the male is typically in 

 Z. niao^rus four and, exceptionallj^, five, it appears to be in Z. 

 grvmoHdii always five, as shown in Plate 1, Figure 7. In other 

 respects Z. griinaJdii is identical with Z. rnacrurus. 



Plate 1, Figure 6, shows the right fifth foot of the male, Figure 4 

 exopod of left fifth foot, and Figure 7 fifth foot of female. 



