392 BULLETIN OF THE BUREAU OF FISHERIES. 



ACANTHOCEPHALA. 



1. Echinorhynchus pristis Rudolphi. [Figs. 8-14.] 



1901. —July 12, 2. July 17, 11, some white, others translucent, others yellowish and others 

 pink. July 19, 7; translucent, white, pinkish ami orange-yellow individuals. Length of female 

 hi niiii. , of male 7 mm. July 30, 15 from one hit. 8 from another; same colors as above; one male 

 noted which was white hut with an orange bursa. When placed in fresh water these worms become 

 turgid. Aug. HO, 1. This species is well adapted to maintain its hold on the mucous membrane of 

 its host by means of the long and slender thorny proboscis and the attenuated anterior end of the 

 body, which is likewise armed with spines. These appliances, together with the tough tissues of the 

 body, are all doubtless needed to preserve the worms when exposed to the anthelmintic action of 

 broken shells and sea-urchin spines which are frequently found tilling the entire length of the 

 alimentary canal of the fish. 



L902.— July Hi, 1 fragment. July 1':!, 3. July 25, 2. Aug. 13, 1. 



NEMATODES. 



2. Immature iirmtlliiilin (Ascaris Sp.). 



1901. — July 11, 1, encysted on viscera; posterior end conical, anal aperture with prominent lips, 

 mouth simple; July 17, several, small; a single diverticulum extending posteriorly from base of 

 oesophagus noted. A small cyst in this lot, when opened, liberated a minute nematode; July 30. 

 This seen plainly to be the type of most common occurrence, viz., with a diverticulum extending pos- 

 teriorly from the base of the icsophagus and an anterior prolongation of the intestine. Also found in 

 another lot of fish examined later on this same date. 



1902.— July 8, 2. 

 :;. Ascaris habena Linton. 



L902. — July 23, 1, female; length 28 mm. 



4. Heterakis sp. 



1901. — Julv 19, 1, female. This worm agrees closely with No. 2 under Scisenops ocellatus. Dimensions 

 in millimeters, life: Length 2.1, length of oesophagus 0.46; diameter, anterior, 0.15; middle 0.22. at 

 anal aperture 0.06; distance of anal aperture from posterior end 0.77; distanceof genital aperture from 

 anterior end 0.4. See also under Lophopseita and Paralichthys. 



5. Small nematodes. [Figs. 35-42.] 



These, which may indeed represent different species, were seen by me for the first time in the 

 summer of 1902. They are minute nematodes provided with a few bristles, especially near the 

 anterior end, a circular pit on each side of the head, and the body curved much like the letter C. 

 Such minute forms, while of much interest, are rather too small for satisfactory study in the kind of 

 survey contemplated in this report. 



1902. — July 8, few; minutely, but distinctly, transverse-corrugate. Usually with a few straight, 

 slender, sharp spines at the anterior end and sparsely scattered on the body. This feature was 

 not observed on all. Reproductive aperture of female near the middle of the body. A single 

 comparatively large ovum and what were taken to be several smaller ova were noted. Dimensions 

 of a female, life, in millimeters: Length 1.4; length of oesophagus 0.22; diameter, anterior 0.043, at 

 genital aperture O.OSli, at anal aperture 0.046; distance of genital aperture from anterior end 0.75; 

 distance of anal aperture from posterior tip, 0.075. July 28, rather numerous, very small. Aug. 4, 

 few, same type as foregoing, among them one male, which was larger than the females, and may 

 belong to another species. The tail was much elongated. The spicules are shown in figure. Aug. s, 

 few, males and females. If these really belong to the same species there is a remarkable difference 

 between the heads of the two sexes. Fig. 35 shows a view of the posterior end of a male from this 

 lot. Aug. 11, 5, identical with those found on July S. Aug. 18, several, males and females. The 

 females agree with type of July 8. The head of the male differs from this type, sec figs. 38 and 39. 

 Length, 1 mm. Aug. 21, tew, same as type of July 8, minute, bristly, with circular pit on each side 

 of head. 



6. Small nematodes. [Figs. 43-48 and 51-54.] 



11KI2. July 17, 2, males. [See figs. 53 and 5-1.] Dimensions, life, in millimeters: Length 3; 

 diameter, head 0.045; at base of oesophagus 0.09, from which point it is nearly uniform to the anal 



