6 PKOCEEDINGS OF THE NATIONAL MUSEUM vol. 75 



RHABDOMBTRA SIMILIS RANSOM, 1900, TRANSFERRED TO GENUS 



PAItUTERINA 



RJiabdometra similis Ransom, 1909, was described originally from 

 material lacking scolices. Linton (1927) reported R. similis from 

 the same host, Coccygus mnericanus, from which the earlier material 

 was collected and described the scolex as bearing a double crown of 

 small hooks on therrostellum. In so far as was possible, toto mounts 

 of Linton's material were compared by the present writer with the 

 type material of R. similis; mature and gravid segments of the two 

 are similar, showing no more than ordinary variation within a 

 species. Linton writes that sections of the more recent material 

 agree in detail with the transverse section of R. similis as described 

 by Ransom (1909, fig. 24). 



The generic diagnosis of Rhahdom.etra^ subfamily Paruterininae, 

 includes the character of a scolex which is unarmed and without 

 rostellum, while the genus Paruterina differs from RhahdoTnetra 

 chiefly in the occurrence of a rostellum armed with a double row 

 of hooks. R. similis is found to fit the generic diagTiosis of Paru- 

 teHna in all respects, and to be distinguishable from other described 

 species of that genus by the size and number of hooks, position and 

 size of cirrus pouch, and the number of testes. In addition to having 

 an armed scolex, R. similis is found to differ consistently from all 

 other species of Rhdbdotnetra in having comparatively few, only 20 

 to 24, bundles of fibers in the inner layer of longitudinal muscles. 

 It is of interest that this condition is definitely described for a 

 species of Parutenna^ P. amjustata Fuhrmann, 1906. It is concluded 

 that R. similis should be transferred to the genus Paruterina as 

 PcmUerina similis (Ransom, 1909) Jones, 1929 (the present paper). 



