ART.i TBEMATODE PARASITES OF BIRDS LINTON 17 



tral sucker 0.24; ova 0.087 by 0.054; oral 

 spines about 0.06 in length and 0.018 in 

 breadth. (Cat. No. 7933, U.S.N.M.) 



This specimen suggests Dietz's Monilifer 

 spinulosus Rudolphi (Zool. Jahrb. Sup. 12, 

 pp. 465-470, pi. 15, fig. 51) and Looss's Ecliin- 

 ostow/wm ew^porum Looss (Zool. Jahrb. 12, 

 pp. 686-7, pi. 25, figs. 16, 17). 

 1913, December 31. 1. In formalin, length 2.85, breadth 0.55. Di- 

 mensions in balsam : Length 1.96 ; maximum 

 breadth, at level of testes, 0.45; diameter of 

 oral sucker 0.12, of pharynx 0.07, of ventral 

 sucker 0.28; length of pharynx 0.10; ova 

 0.078 by 0.054. 



APORCHIS RUGOSUS, new specfes 

 Figures 43-49 



A distome from the intestine of an Arctic tern {Sterna paradisea) 

 at Woods Hole, August 17, 1912, although no oral spines were pres- 

 ent, is referred to Fuhrmann's genus Aporchis. 



Dimensions in life: Length 17 mm.; breadth, anterior 0.22, at 

 ventral sucker 0.44, about middle of length 0.73, towards posterior 

 end, maximum, 1.12; ovum, exclusive of the long filament, 0.11 

 by 0.03. 



Body elongate, slender, tapering gradually to the anterior end 

 from a point near the posterior end, which is very slightly narrowed 

 and bluntly rounded. Mouth subterminal, head reniform; no oral 

 spines present, but what were interpreted as faint indications of 

 evanescent spines were seen. Neck covered with blunt, papillate 

 spines in close, transverse rows. Spines on anterior part of the 

 body rather irregularly placed, becoming sparse at level of anterior 

 limits of the vitellaria. On the lateral margins these papillate 

 spines are very irregular (fig. 47), and show a tendency to slough off. 

 The posterior third of the body is distinctly serrate on the lateral 

 margins. (Fig. 48.) 



Dimensions in balsam : Length 16 mm. ; breadth of head 0.17, at 

 level of ventral sucker 0.35, at middle of length 0.70, near posterior 

 end 0.80; diameter of oral sucker 0.09, of pharynx 0.05, of ventral 

 sucker 0.22; ovary, length 0.14, breadth 0.26; first testis, length 0.22, 

 breadth 0.39 ; second testis, length 0.25, breadth 0.35 ; ova from 0.08 

 to 0.11 in length, excluding the long filament, and about 0.03 in the 

 shorter diameter ; distance of anterior border of ventral sucker from 

 anterior end 0.35. 



70841—28 2 



