398 Cr. A. MacCallum, 



beginniiig- of tlie uterus. The uterus, siirrounded here by a niaiitle 

 of Shell giand cells, makes its way upward toward the genital pore 

 along the inside of the right vitellarium. The vitellaria are very 

 plentiful and extend from nearly opposite the orifice of the vagina 

 down each side caudad to alniost the sucker disc. 



The testes are relatively large but few in number, tliere being 

 only about 18 or 20. The Vas deferens passes anteriorly on the 

 left side. No eggs are seen in any of the specimens mounted so 

 that at this writing no measurements of them can be given. 



The suckers have the usual chitinous reinforcement, a drawing 

 of which is given in Fig. C c. 



The rest of the measurements etc. are given at the end of this 

 description. 



Measurements : 



Length: 4,4 mm. Width: 0,3 mm. 



Width of head: 0,12 mm. 



Size of oral suckers: 0,5 mm. 



Sucker disc: 1 mm long, 0,4 mm wide. 



V. 0.: Armed situated short distance posterior to g. p. 



and dorsal. 

 Number of suckers: 59 — 0,03 X 0,02. 

 Number of Testes: 20 — 0,06. 

 Habitat: Gills of Holacanthus angelichthys. 

 Locality: Aquarium, New York. 



Microcotijle arcJiosargi n. sp. 



This form is to be found on the gills of the marine Sheep's 

 head, Archosargus probatocephalus, and is so delicate as to be almost 

 invisible when alive and in situ. It measures 8 by 0,8 mm and is 

 much elongated, becoming very slender just in front of the asymme- 

 trical spreading caudal disc (Fig. Da). 



The mouth is terminal and supplied with the usual lateral 

 suckers which are provided with a marginal membrane and sub- 

 divided by a distinct partition. The delicate pharynx passes into a 

 Short esophagus which gives rise as usual to two intestinal rami. 



The common genital pore is surrounded by spicules which are 

 arranged as shown in the figure (Fig. De). Almost immediately 

 behind this on the dorsal surface lies the opening of the vagina, 

 also surrounded by an armature of spicules. 



