PARASITES OF FISHES OF THE WOODS HOLE REGION. 439 



Many spheric'iil Ijcidies «ith ciiiict'iitrir structure were noted in tlie contents of the excretory 

 vessels. The hirgest of these measured 0.016 mm. in diameter (7, p. 28S) . 



While watching a living sjiecinien a curious j>henomenon was observed in the vicinity of the 

 slicU gland. A fine hair-like hody which lay in several coils ajipeared to be turning rather rapidly 

 around a central .space. A somewhat sinular appi'arance was present in two smaller spaces nearby. 

 The specimen, while still living, had been partly stiffened liy holding the compressor over the llame 

 of an alcohol lamp for a few seconds. This phenomenon evi<lently has something to do with the 

 foriiiatii>n of the eggshell, but jnst what I could nipf make out. 



Pomolobus pseudoharengus, Ah n'ifi'. 



Only ynung have been examined. Thirty-six were exannned in .Inly and August, 1899, r>ii five 

 different occasidus. In all of them the alimentary canal contained co|)epods, sometimes in enormous 

 numbei's. In the summer of 1900 (July 9 and August 10) fourteen specimens were examined, and 

 in addition to copepi ids young squid and large uund.iers of small shrimp were found. These specimens 

 were taki'U at AVareham and were larger than the fish examiaeil the year before. About the same 

 entozoa arc fnund in the ynung alewifc as in the young herring, with which they are a.ssociated. 



NEM.\TonES. 



1. Xeiiiiitiiih'x, imniatiH-c. .\. few fciund in one lot in 1S99 (.\ug. 15). 



l-RSTODES. 



2. Lari'itl ccxtodi^s [Umlex polijmorphiif Pujardin). Free in intestine. Aug. .'5, 1899. For account of 



similar forms, see 4, 789-792. 



TKEM.VTODES. 



Olitaini-d by washing out the aliuK'Utary canal and decanting the material. 



3. DisUiinaiii iippeiiiliciildlntn Rudolphi. Fnund on all occasions in 1899, usually numerous. Aug. 10, 



1900; very numerous. See 7, p. 289, pi. xxxvi, figs. 25, 20. Measurements of living sjiecimens 

 in one lot, 1.28 mm. to 2.ofi mm. 



4. DiMuniaiii rildlmviii Linton. See 7, p. 290, \A. xxxvii, iigs. 38, 39; also under ( 'hi/ua liareiujiis, No. (1. 



5. Plutonium hnlhryiipharoii Olsson {?). [PI. xxxii, figs. 3.55, 35(5.] See umlcr ('liijiiu Imri-iii/iis, No. 7. 



Aug. 2, 3, and 19, 1899; very few. 

 Body smooth, shiprt, fusiform; neck conical; tail tapers to a point. ( Iral sucker nearly circular 

 in ventral view, aperture broadl)' triang\ilar; pharynx subglobular, close to (iral sucker; tcsophagus, 

 none; rami of intestines simjile, extending nearly to posterior end. Acetabulum in middle of body, 

 prominent, about twice the diameter of the oi'al sucker, aperture transverse. Testes tw'O, rather small, 

 oval-elliptical, immediately behind the acetabulum. Ovary behind testes. F-xact position not clearly 

 determined. Vitellaria a single six or seven lobed mass, lying laterally toward the posterior end. 

 Ova small, elliptical, very numerous, filling all of body back of acetabulum. Re])roductive aperture 

 in front of acetabulum, on median line. I'iniensions in millimeters of sjiecimen in glycerine: Length, 

 0.8; diameter of boily, anterior 0.1, middle 0.3, posterior 0.03; diameter of oral sucker 0.1, iif 

 acetabulum 0.3; testes, 0.07 and 0.05 in two principal diameters; pharynx, length 0.05, depth 0.07; 

 ova, 0.017 and 0.010 in the two ]irincipal diameters. These measurements were made from ventral 

 view, except the pharynx, which wa.s mea.sured in lateral view. 



6. iloKosiloiiiam sji. [PI. \x\iv, tigs. .377-379.] Aug. 19, 1899; 4. Very small, oval or elliptical. 



Dimensions in millimeters: Length, O.B; diameter, 0..34; diameter of genital acetiibulum, 0.07; 

 diameter of oral sucker, 0.07; ova, 0.02 and 0.017 in the two principal diameters. Vitellaria in two 

 masses lying one on either side of genital acetabulum. Uterus very voluminous; body behind 

 acetabulum tilled uitli cva. 



I'ICOTOZOA. 



7. S/iomzijd. Aug. 2, bS99; aiming the iiinsclcs of liack and side. ( If 22 fish 9 were infected. 



Mr. v.. K. Tyzzer says that about half of the young alewives examined by him in 1900 have 

 these cysts in the flesh, but that they are Ic.ss conunon in the larger Hsh. For fuller account, see 

 under Vlupea liareiiyus, No. 8. 



