70 



shorter. The convexity of the U is pointing 

 to the anterior extremity, and very distant 

 from the termination of the esophagus; 

 about at the beginning of the first portion of 

 the intestine. Next to the testicle is a volu- 

 minous deferent duct wich also has the fun- 

 ction of a seminal vesicle. Just at the initial 

 por tion of the deferent canal there is a pair 

 of small diverticula branched into three or 

 four fingerlike prolongations, which in the 

 old males are full of spermatozoids and seem 

 to have also a glandular function, {fig. 1). 

 The deferent canal terminates in an claviform 

 ejaculatory duct with muscular walls which 

 measure about 0,8 mm. in length. The spi- 

 cules (Fig. 1, 4, 5) are subequal, winged, 

 and partly rugose, the rugosities of light 

 colour aie seen only in specimens well clea- 

 red in phenol The spicules measure about 

 0,870 to 1,165 mm. in length. The guberna- 

 culuni is flat, subtriangular when seen from 

 the front, and in the form of a oomma when 

 seen in profile; il measures about 0,1^7 to 

 0,243 mm. in length. The caudal extremity 

 of the males (Fig. 4 and 5) has the ventral 

 surface differentiated and the cuticle rugose 

 for about 1, 3 to 1,7 mm.; it is curved in 

 an are and internally has muscles obliquely 

 directed from the median ventral field to 

 the lateral fields, as observed in the Kathla- 

 nidac. 



In the same specimens the roughened 

 portion is slightly excavated, appearing to 

 form an ample ellipsoid cup with distinct 

 borders. 



The papillae of the caudal extremity are 

 disposed in three groups with three pairs 

 of papillae in each (Fig. 1, 4 and 5). 



The first group is postanal, and the pa- 

 pillae are very small, not arranged in line, 

 and support a very small lateral wing. The 

 second group is adanal and disposed in a 

 straight line, oblique to the lateral fields; the 

 papillae are larger than those of the first 

 group, very near to each other and equidi- 

 stant. The third group is preanal, the papil- 

 lae are large, equidistant, arranged in a 

 straight line parallel to the lateral fields and 

 widely separated one from the other. 



Habitat. This parasite is found exclusi- 

 vely in the large intestine, and especially the 

 cecum of the gambás (Didelphis); we nave 

 material from the following places: Mangui- 

 nhos. Angra dos Reis, collected for us by 

 Dr. QOMES DE FARIA; São Paulo, collec- 

 ted by Drs. FLORENCIO QOMES, CARINl, 

 MACIEL and LUTZ in D. aurita and in São 

 Paulo from D. nudicaudatus, collected by 

 LUTZ. 



It is very common in the gambás where 

 It generally exists in large numbers. 



