32 



PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 88 



mm.; diameter of anterior sucker 0.21 mm., of posterior sucker 

 0.09 mm. 



Twenty-four (U.S.N.M. No. 8175), collected by Dr. C. W. Hahn, 

 August 8, 1910, from silversides ; cysts in flesh behind dorsal fin. Di- 

 mensions, life: Length 1.08 mm.; breadth 0.51 mm.; diameter of an- 

 terior sucker 0.25 mm., of ventral sucker 0.1 mm. Dimensions in 

 balsam : Length 0.87 mm. ; breadth 0.46 mm. ; length of anterior sucker 

 0.15 mm., breadth 0.22 mm.; length of ventral sucker 0.08 mm., 

 breadth 0.09 mm. 



Eighteen (U.S.N.M. No. 8176), collected August 27, 1928, from 

 kingfish. These are small, minutely spinose gasterostomes of very 

 diverse shapes. In general they are more or less pyriform, tapering 

 more posteriorly than anteriorly. Anterior suckers relatively large, 

 opening ventrally. In some there is a small buttonlike projection 

 in front of the anterior sucker, as in some of the forms from the gar. 

 The shape depends in part on the condition of the cirrus ; when it is 

 everted the posterior third of the body is more or less cylindrical; 

 when the cirrus is retracted the body may be ovate or pyriform. The 

 relative positions of the testes and ovary are subject to some differ- 

 ences depending on the state of contraction, and particularly on their 

 adjustment to the relatively large cirrus pouch. The vitellaria are 

 in front of the other genitalia, except that they may be overlapped 

 by foldsl of the voluminous uterus. In a typical example there ap- 

 peared to be about 16 follicles of the vitellaria on each side of the 

 median line forming a continuous band of follicles across the body 

 just behind the anterior sucker. The ova were packed so closely that 

 it was difficult to make satisfactory measurements. They are thin- 

 shelled and about 0.012 by 0.008 mm. to 0.015 by 0.009 mm. in size. 



Table 10. — Measurements of four specimens of Prosorhynchiis gracilescens in 



balsam 



Measurement 



Length 



Breadth 



Anterior sucker, length 



Anterior sucker, breadth... 

 Diameter of ventral sucker. 



Mm. 



0.67 



.31 



.17 



.17 



Mm. 



0.66 



.22 



.14 



.14 



Mm. 



0.78 



.29 



.15 



.15 



Mm. 

 0.81 

 .30 

 .13 

 .17 

 .08 



Specimens collected from garfish on one date in July, three dates 

 in August, eight dates in September, and one date in October, over a 

 period of seven years during 1907 to 1928. In July, 8 from 1 fish, in 

 August, 45 from 15 fishes, in September, 767 from 11 fishes, in Octo- 

 ber, 7 from 1 fish. The greatest number obtained from a single fish 

 was 229, on September 9, 1923 (U.S.N.M. Nos. 8177-8178). 



