Hehninth Fauna of the Dry Tortugas. 49 



Dimensions, life, flattened: Length 1.35; breadth 0.40; oral sucker 

 0.14; pharynx o.ii; ventral sucker 0.21; ova 0.036 by 0.017. 



1907, July 12,1 distome, length 1.75. 



Host, HcemuloH plumiei'i: July 13, 1906, 2 fish, i distome. 



Dimensions, life: Length 1.75; breadth, anterior 0.16, base of neck 

 0.50, middle 0.40, posterior 0.21 ; oral sucker 0.14; pharynx 0.07 ; ventral 

 sucker 0.20; ova 0.037 t>y 0.020. Body filled with minute ovate bodies, 

 0.003 ill length, not seen in the mounted specimen. 



1906, July 8, I fish, I distome; July 15, i fish, i distome. 



1907, June 27, 2. fish, i distome; July 6, 16 fish, 6 distomes; July 8, 

 2 distomes; July 10, few distomes; July 12, few distomes; July 

 13, I distome. 



1908, July 3, 2 fish, I distome; July 6, 5 fish, i distome; July 9, i fish, 

 2 distomes ; July 10, 5 fish, i distome; July 11, 2 fish, i distome; 

 July 12,1 fish, I distome; July 14, 14 fish, few distomes. 



Host, Hcemulon sciuriis: 



1907, June 28, I fish, i distome. 



1908, July 2, I fish, I distome. 



Dimensions, life: Length 1.20; breadth 0.25; oral sucker 0.08; 

 ventral sucker 0.15; ova 0.030 by 0.015. 



Host, Calamus calamus: 



1907, July 6, I fish, I distome; July 10, 2 fish, i distome. 



Dimensions, life, flattened: Length 1.47; breadth 0.53; oral sucker 

 0.13; pharynx 0.08; ventral sucker 0.21; ova 0.041 by 0.017. Scattered 

 among the ova and also in other parts of the body were immense numbers 

 of small oval bodies, 0.007 by 0.004. These are not evident in the 

 mounted specimen. 



Deretrema fusillus gen. et sp. nov. (Figs. 102-1043.) 



Etymology: '^;V"J, neck; -/'^^'-t, hole. 



The description which follows is based on a distome from Ocyurus 

 chrysurus (fig. 102). Other distomes from Hcemulon macrostomum and 

 Abudefduf saxatilis are referred to the same species with some hesitation. 



Body smooth, in living specimen crossed by minute, transverse, 

 wavy lines, close together and occasionally reticulated. Color in life 

 translucent yellow, deeper amber near center when slightly flattened, 

 ventral sucker with reddish granular pigment, ovary pink by transmitted, 

 white by reflected, light. The shape is fusiform, the greatest thickness 

 being at the middle through the ventral sucker, tapering to a bluntly 

 rounded point at the anterior end and to a sharper point at the posterior 

 end. The oral and ventral suckei's are each nearly circular in outline, 

 the ventral being more than 1.5 times the diameter of the oral. Pharynx 

 adjacent to oral sucker, broader than long; esophagus broad and thin- 

 walled; intestines almost entirely concealed by the uterus. Reproduc- 

 tive aperture on left side at about level of the bifurcation of the intestine ; 

 cirrus short; cirrus-pouch incloses the seminal vesicle, which is oval and 

 lies transverse to the axis of the body. No prostate was seen, but a few 

 cells around the cirrus probably represent that organ. Testes 2, lateral, 

 4 



