90 



BULLETIN 120, UNITED STATES NATION AJ. MUSEUM. 



upon the basis of study of such scant material. With this species, 

 in my material, are more numerous individuals of another, much | 

 smaller species, ZellerieTla atelopyxena, to be described later. 



ZELLERIELLA COUCHII, new species (fig. 56, p. 89). 



Type.—UmiQA States National Museum Cat. No. 16463. 

 Host. — ScapMopus couchii Baird, two scant infections in United 

 States National Museum specimens both numbered 13629, from 

 Helotes, Texas, November 30, 1883, G. W. Marnock, collector. 



Measure'tnents of a large individual. — Length of body 0.16 mm.; 

 width of body 0.087 mm. ; thickness of body 0.016 mm. ; diameter of 



nucleus 0.0144 mm. ; length of en- 

 dospherule 0.0025 mm. ; width of 

 endospherule 0.002 mm. ; cilia line 

 interval, anterior 0.0016 mm.., mid- 

 dle 0.003 mm., posterior 0.0033 mm. 

 Six, or possibly eight, chromo- 

 some masses are seen. The ecto- 

 sarc is quite thick (fig. 56, h). 



This is a smaller form than 

 either Z. hypopacheos or Z. \_ate- 

 Jopodos]. Its nuclei are relatively 

 smaller and lie farther back in the 

 body. Two shapes of the body 

 may be noted, one (fig. 56, a and c) 

 rather wedge-shaped and narrower 

 than Z. hypopacheos or Z. [ate- 

 lopodos~\ , the other more rounded 

 (fig. 56, h). In several nuclei 

 six chromatin masses were fairly 

 clearly seen. In another case, more 

 obscure, there seemed to be eight. 

 No nuclei were found in an ana- 

 phase of mitosis, the favorable phase for counting the chromosomes. 

 It is unsafe to judge the number of chromosomes from any other 

 stage of mitosis, though it is probable that six is the number of the 

 jnassive chromosomes in this species. 



ZELLERIELLA SCAPHIOPODOS, new species (fig. 57, above). 



Type. — United States National Museum Cat. No. 16464. 



Host. — Scaphiopus solitarius Holbrook, from Ealeigh, North Caro- 

 lina, September, 1908; H. H. and C. S. Brimley, collectors. 



Measurements. — Length of body 0.155 mm. ; width of body 0.09 

 mm. ; thickness of body 0.013 mm. ; diameter of nucleus 0.0213 mm. ; 

 cilia line interval, anterior 0.0026 mm., posterior 0.00375 )iim. 



Fig. 57. 



-ZELLEKIELLA SCAPHIOPODOS, 

 460 DIAMETERS. 



