CESTODES FROM FISHES — LINTON 431 



There is considerable variation in the proportions of the scolex. Thus, 

 the length, breadth, and thickness of two in formalin were 0.75, 0.72, 

 0.55 and 0.9, 0.97, 0.73 mm.; another in glycerm: Length 1.65, breadth 

 0.43 mm. Following are lengths and breadths of scoleces in balsam: 

 0.3 by 0.19, 0.31 by 0.25, 0.42 by 0.28, 0.5 by 0.32, 0.5 by 0.36, 0.7 

 by 0.38, 0.98 by 0.28, 1.4 by 0.28, 1.7 by 0.25 mm. Measurements of 

 the first segment in a typical strobila: Length 0.07 mm., breadth 

 0.56 mm. In an immature strobila with maximum breadth about 1 

 mm., the length of the first segment was 0.15 mm., anterior breadth 

 0.22 mm., posterior 0.35 mm. Ova thin-shelled and in most cases 

 collapsed in sections and balsam mounts; average of 10 : 0.068 by 0.039 

 mm. ; largest 0.075 by 0.045 mm. ; smallest 0.06 by 0.036 mm. 



Specimen from Apeltes quadracus. — One collected April 21, 1911; 

 12 fishes examined. Length in formalin 31 mm., breadth 2,8 mm. 

 Measurements in balsam: Length 16 mm., breadth 2.4 mm.; scolex 

 length 0.84 mm., anterior breadth 0.24 mm., posterior 0.35 mm.; 

 first segment length 0.24 mm., anterior 0.48 mm., posterior 0.58 mm.; 

 ova thin-shelled, average of 19 : 0.063 by 0.036 mm. (U.S.N.M. No. 

 8880). 



Specimen from Cyclopterus lumpus. — One collected May 6, 1913; 

 7 fishes examined. Length ui formalin 90 mm. Measurements in 

 balsam: Scolex length 0.6 mm., thiclvness 0.3 mm.; first segment length 

 0.06 mm., breadth 0.24 mm.; posterior segments, length 0.56 mm., 

 breadth 1.4 mm.; median segments, length 0.21 mm., breadth 1.96 

 mm.; ova 0.054 by 0.03 (pi. 61, fig. 13) (U.S.N.M. No. 8881). 



Specimens from Gladiunculus bispinosus. — Recorded from this fish 

 by Cooper.^" 



Cestodes (U.S.N.M. No. 8882) referred to this species were collected 

 by Edwards from the stickleback as follows: April: 12 on four dates, 

 450 fishes exammed; 23 on two dates, number of fishes examined not 

 recorded. May: 7 on two dates, 120 fishes examined; 25 on three dates, 

 number of fishes examined not recorded. June: 4 on two dates, 80 

 fishes examined ; 1 on one date, number of fishes examined not recorded. 

 Collections made in five different years. Maximum length 75 mm., 

 maximum breadth 2.7 mm. Scoleces elongate to very short; bothrial 

 pits extend to base of scolex; first segments, except in immature strobi- 

 lae, short, crowded, much broader than long. Ova thin-shelled, about 

 0.51 to 0.63 by 0.3 to 0.42 mm. 



Measurements in balsam: Length 18 mm.; maximum breadth 

 2.1 mm.; scolex length 0.21 mm., breadth 0.28 mm.; first segment 

 length 0.08 mm., breadth 0.35 mm.; last segment length 0.28 mm., 

 breadth 0.91 mm.; ova 0.051 by 0.033 mm. Ova appear about 4.27 

 mm, from anterior end. 



16 Illinois Biol. Mon., vol. 4, p. 404, 1919. 



