26 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 82 



3. Exopod of male right fifth foot composed of one segment-- soldatovi Rylov 

 Exopod of male right fifth foot composed of two segments — 4 



4. In female no processes on sides of genital opening ; in male ar- 



mature of swimming feet symmetrical saliens Lilljeborg *' 



In female processes on sides of genital opening; in male arma- 

 ture of some of swimming feet symmetrical 5 



5. In female a dentiform projection on each side of genital area ; in 



male exopods of swimming feet 2 to 4 modified borealis Fischer " 



In female trilobate processes on each side of genital opening; 

 in male first, third, and fourth swimming feet symmetrical, 

 exopod of right second foot much modified. 



septentrionalis Juday and Muttkowski 



HETEROCOPE SEPTENTRIONALIS Juday and Muttkowski 



Plate 14, Figures 1-S 



Heterocope septentrionalis Juday and MuttxvOWSKI, 1915, pp. 27-31, tigs. 4-6. — 

 Mabsh, 1920, pp. 5, 6, pi. 2, tigs. 3, 5, 6, 8-13.— Ryxov, 1924, pp. 225-232. 



The abdomen of the female (pi. 14, fig. 3) consists of three seg- 

 ments, the first being nearly equal to the combined length of the 

 second and third ; the second and third are of about the same length. 

 The genital area bears two trilobate processes (pi. 14, figs. 5-7). 

 Though these are typically trilobate, there is much variability in 

 their form and sometimes they may be bilobate, as in Figure 7. The 

 length of the furcal rami is about li^ times the breadth. They are 

 ciliate on the inner border, and in addition to the three setae, typi- 

 cal of the genus, bear at the inner and outer distal angles short and 

 slender setae. 



The first antennae may slightly exceed the first abdominal seg- 

 ment. The second antennae are like those typical of Heterooope, 

 the exopod consisting of seven segments, three short central and one 

 short terminal. 



The swimming feet are symmetrical. The fifth foot of the female 

 (pi. 14, fig. 8) is like those typical of the genus. The second basipod 

 and the first exopod are armed with spines at the outer distal angles. 

 The second exopod bears two spines externally, a terminal claw 

 which exceeds in length the segment, and in the inner border four 

 hooklike teeth ; these teeth are each armed with one to three denticles. 

 There is a minute spine between the distal external spine and the 

 terminal claw. 



In the male the first, third, and fourth swimming feet are sym- 

 metrical. The right exopod of the second foot is quite different from 

 the left (pi. 14, fig. 2) ; the spine of the first segment (pi. 14, fig. 4) 

 is much enlarged and armed with denticles, which are more irregu- 



" Synonyms : H. romana Imhof, H. rohusta Sars, H. alpina Sara. 

 "Synonyms: H. robusta Grube, H. saliens Nordquist, //. loeismavni Imhof. 



