14 PROCEEDIISrGS OF THE IST ATIONAL MUSEUM VOL. ts 



the post-testicular region is filled completely with the vitellaria. 

 Usually the testes are situated a little in front of the middle of the 

 post-acetabular region of the body. 



Average length of 24 specimens in balsam 3.93, average maximum 

 breadth of same 0.43. Of these the longest measured 6.13 in length 

 and 0.49 in breadth ; the shortest, 1.44 in length and 0.22 in breadth ; 

 the broadest, 2.52 in length and 0.68 in breadth ; the narrowest, 1.44 

 in length and 0.22 in breadth. Transverse diameter of oral sucker, 

 average of 18 in balsam, 0.11, of pharynx 0.06, of ventral sucker 0.27 ; 

 length of pharynx, 0.10. 



Dimensions of testes, average of 13, in balsam : First testis, length 

 0.32, breadth 0.32; second testis, length 0.39, breadth 0.33; shortest 

 first testis, length 0.14, breadth 0.42 ; longest first testis, length 0.55, 

 breadth 0.34 ; shortest second testis, length 0.20, breadth 0.38 ; longest 

 second testis, length 0.67, breadth 0.42. 



Anterior limits of vitellaria in 30 mounted specimens : Anterior 

 edge of first testis 6; between the middle and anterior edge of first 

 testis 13; between posterior edge and middle of first testis 10; pos- 

 terior edge of second testis 1. Distance of posterior margin of second 

 testis from anterior end, average of 29, 2.04; same from posterior 

 end 1.54, a ratio of 4 to 3. Departures from this ratio were : 2.10 to 

 2.59, or a ratio of 4 to 5, and four cases where the ratio was 2 to 1. 

 The greatest departure from the ratio 4 to 3 is the example from the 

 loon (fig. 42), where the ratio is 1.74 to 0.36, or nearly 5 to 1. This 

 specimen suggests Dietz's MonUifer spinulosus (Rudolphi). 



HECOED OF COLLECTIONS 



Lat^s argentatus. 



1913, April 8. 14. Note on formalin material: Anterior half 



of body white, posterior filled with vitel- 

 laria, bluish; larger example, length 5.80, 

 breadth 0.64; smaller example, length 3.80, 

 breadth 0.38. 



1916, August 13. 5. (Cat. No. 7926, U.S.N.M.) 

 September 1. 1. 



1917, January 17. 1. 



18. 28. In the younger individuals the testes are 

 contiguous, the anterior more or less quad- 

 rangular, the posterior somewhat triangular 

 in outline. In the older specimens the testes 

 are elliptical in outline and are separated by 

 a short interval. Dimensions in balsam: 

 Length 3.5 ; diameter of head 0.30 ; maximum 

 diameter, a little way back of ventral sucker. 



