470 BT^T.LETIN OF THE UNITKD STATES FISH COMMISSIOX. 



Dimensions iu millimeters: 



Length 



.Miixiiriuin (iiiiiiu-ier 



l.tiiu'lh of oral sucker 



Hrt'ucUh of onil sucker 



IA■Il^'Iil of ucctnbiilum 



KrciuUhof HCctalmlum 



LLiil,'th iif pharynx 



HniKllli (if i>liii"ryiix 



l^piij^iT eiiiinu'tcf of ovum. 

 Shorter diamelur of ovum. 



H. Monoslomutit riinil-iduiirtlnii si\). nov. [I'l. x.vxiv, figs. 373-376.] Anft. 5, ISitii: 7. .Inly L'<i. IIKKI; 

 Aug. 4 and 10, 1900; inimerou.". Young an<l adult together in .«aine lot. 



The following preliminary synopsis of the.se intere.sting treniatodes is here given: BfMly thickish, 

 depre.ssed, slightly convex above, flat helow, outline varying liut approximating ovate, covered with 

 exceedingly minute villous spines. Oral sucker circular, subterminal, aperture nearly circular. 

 Pharynx varying in preserved specimens, suhglobular iu life near oral sucker, but in favorable iiositions 

 seem to be separated by a sliort canal. G"lsophagu.s short; intestinal rami two, simple, extending to 

 jjosterior enil of body. Testes in the larger specimens apjian-ntly eight, four on each posterolateral 

 margin (in one specimen there were five on the right side and four on the left) . In smaller si>ecimen.« 

 the test<'s are in two lateral clustei-s of four or five or more te.sticules each, situateil at alKiut the posterior 

 third, w hich in such si>ecimens is usually the widest part of the body. Seminal vesicle on meilian line, 

 curving to the left, the cirrus o|)ening by an acetabuliform aperture about the anterior third. The 

 vitellaria are dendritic organs, distributed generally in the iiosterior part of the body behiml the 

 genital acetabulum in younger specimens, conlined to the lateral regions of the middle third of 

 the ix)dy of older specimens. Ovary a many-lobe<l organ on the median line a short distance behind 

 the genital acetabulum, from which it is separated by the seminal receptacle and base of t lie cirrus 

 pouch. Kxcretory ve.ssels very numerous in the anterior third of the l)ody, each opening independently 

 on th(; surface. Uterus very voluminous, in the oMer specimens filling u]) all the posteromedian i)art 

 of the boily. Ova rather small and elliptical. Dimensions of a living s])ecimen slightly compressed, in 

 millimeters: Length, 'l.'.Ur, diameter of oral sucker 0.2.">, of i)harynx 0.1."), of genital acetabulum O.l.S; 

 ova, 0.021 and 0.010 in the two principal diameters. At certain ages there is a very characteristic 

 coloration in the.se worms, due to the different ages of the ova. The beginning folds of the uterus on 

 the left side are opa<|ue white; the next, toward the posterior an<l on the right si<Ie, are light yellow, 

 shading into amber and smoky brown, iHM-oming much darker toward the anterior. 



The external opening of the uterus was not made out, although a minute aperture was noted in 

 one specimen which had lain over night in salt solution 0.07 nun. in front of the genital acetabulum. 

 This point will doubtless be .settled when the specimens are sectioned. 



Prionotus caroliuus, .SVk Unhiu. 



Stomachs and intestines of this sjiecies have yielde<I a variety of material. In one specimen were 

 found a young herring, several young clams (Mi/ii), two shrimp { Piiln moiuiex) , :u\i\ a pebble. Small 

 specimens have yielded shrimiis in large numbers, ani]>hipods and other small crustaieans, sipiid ami 

 lamellibranch iimlhisks, annelids, ami .seaweed. Oiic small siK'<imen bad four youui.' winter tlounders 

 in its stomach 



NEM.\TOI>ES. 



I. Immature nemntoihs. On .serous covering of viscera. Aug. 21, 1899; Aug. 21, 1900; few. 



Some immature a.scarids collecteil .July 21, l.S,S7, encapsule<l in peritoneum. Dimensions in 

 millimeters: Length, 20; diameter of head O.ll, 1 mm. from anterior 0.27, maximum 0.56, 1 nun. from 



