ART. 16 HELMINTH PARASITES OF THE OPOSSUM — CHANDLER 



are less constant. There are two pairs of small papillae, ventral 

 in position near the tip of the tail, but in some individuals one of 

 these is barely distinguishable. Slightly in front of the more an- 

 terior of these there is a more laterally placed pair of small papillae, 

 usually a little nearer to the tip of the tail than to the cloaca. Be- 

 tween the cloaca and the two pairs of ventral papillae near the tip 

 of the tail there are three or four pairs of very small papillae, sit- 

 uated near the mid ventral line. In addition to these there are five 

 to seven pairs of more laterally placed papillae in a row beginning 

 posterior to the clo- 

 aca and extending to 

 the level of the suck- 

 er. These are very 

 difficult to discern, 

 and could not be seen 

 at all in a young 

 specimen examined. 



Host. — Didelphis 

 virginiana. 



Location. — Cecum. 



Locality. — Hous- 

 ton, Tex. 



T'yj)& specimen. — 

 U.S.N.M. Helm. 

 Coll. No. 8549 ; para- 

 types, No. 8550. 



Remarks. — Five species of the genus Aspidodera have hitherto 

 been described, all from the South American opossums and edentates. 

 Two of these, A. fasciata and A. hinansata, are believed by Tra- 

 vassos (1913) to be identical. A. fasciata has a large number of 

 caudal papillae, 40 on each side. A. hinansata has the principal 

 papillae arranged in an identical manner, but it was described from 

 badly preserved material, and not all the papillae could be ob- 

 served. A. scoleciformis has 9 papillae on each side of the male tail, 

 2 anterior to the sucker, 1 just behind it, 3 near the anus, and 3 on 

 the tail. A. sulmlata has only 3 pairs of caudal papillae on the male, 

 2 anterior to the sucker and 1 just behind the anus. A. raillieti has 

 10 pairs of caudal papillae in the male, 2 pairs anterior to the sucker, 

 1 pair just behind it, 1 at the level of the anus, 1 pair rather medially 

 situated shortly behind the anus, and 5 pairs on the distal half of the 

 length of the tail. In A. harwoodi the arrangement of the larger 

 papillae is very must as in A. raillieti, but in fully mature specimens 

 there are, as described above, as many as 18 pairs of papillae in all. 



Figure 4.- 



-Aspidodera harwoodi, new species, tail of male 



