60 PROCEEDINGS OF THE NATIONAL MUSEUM vol.88 



the levels of testes and ovary, begin again on front of the ovary, 

 and continue in the anterior fragment along each lateral margin in 

 a band about one third the breadth of the body. The anterior frag- 

 ment is very densely spinose, the spines continuing to the level of 

 the first testis, where they are sparse; length of spines about 0.01 

 mm.; testes long-oval, ovary nearly circular in outline; shell gland 

 in front of ovary; no seminal receptacle seen; some indication that 

 the supply of sperm had been exhausted, numerous nucleated cells, 

 apparently unfertilized germ cells, lying in the uterus associated 

 with the ova. 



Family ECHINOSTOMIDAE Looss, 1902 



Subfamily Echinostominae Looss, 1899 



Genus ECHINOSTOMUM Rudolphi, 1809 



ECHINOSTOMUM species 



In June, 1915, twelve trout perch (Percopsis omiscomaycus) from 

 Constantia, N. Y. (Oneida Lake), collected June 6, were sent to me 

 for examination. Dr. Tarleton H. Bean in an accompanying letter 

 stated that the collector reported that about 5 percent of the fish had 

 "something wrong with the eyes." The fish had been taken from a 

 small stream into which they had come to spawn. No distomes were 

 found in any of the abnormal eyes. Tissues from diseased and from 

 normal eyes were examined for bacteria by E. S. Linton. Numerous 

 short bacilli were found in the abnormal eyes, none were found in 

 the normal eyes. Two encysted distomes were found in an apparently 

 normal eye, one in the connective tissue outside the eyeball, the 

 other in one of the eye muscles; diameters of cysts 0.4 by 0.3 mm. 

 and 0.3 by 0.22 mm. ; distomes with a single circle of about 24 spines 

 around the mouth, length of spines 0.04 mm. ; neck spinose. In one 

 of the fishes an eye which seemed to be more prominent than the 

 other was opened and an encysted distome found in the teased mate- 

 rial, apparently from the connective tissue surrounding the eyeball; 

 body of distome minutely spinose ; single circle of spines, 20 or more, 

 around the mouth; length of spines, 0.035 mm. Length of distome, 

 0,34 mm. Another slightly bulging eye was examined and two en- 

 cysted distomes found. The larger cyst measured 0.56 by 0.5 mm. 

 What appears to be this specimen, compressed and mounted in balsam, 

 is 0.8 mm. in length; diameter of crown of spines, O.lT mm.; length 

 of spines, 0.04 mm. ; number of sjDines about 30 ; diameter of ventral 

 sucker, 0.07 mm. The smaller cyst, 0.33 by 0.22 mm. ; number of oral 

 spines 20 or more ; length of spines 0.035 mm. Another cyst adhering 

 to the outside of an eyeball measured 0.37 by 0.34 mm. ; distome with 

 about 18 oral spines. (U.S.N.M. No. 8213.) 



