582 PRdCEEDlNati OF THE NATIONAL MUSEUM. vol.58. 



NEMATODIRUS FURCATUS. new species. 

 Plate 29, fig. 1 ; plate 31, fig. 19 ; plate 34, figs. 27-28. 



Specific diagnosis. — N ematodirus : Species very small. Male, 6 to 

 6.4 mm. long and 65 to 70 [x in greatest diameter. Bursa resembles 

 that of N. -filicollis, with rays relatively thinner and longer. Bosses 

 smaller. Spicules, 0.50 to 0.80 mm. long, separated throughout the 

 distal third or more, each one ending as a beveled tube. Length of 

 esophagus, 0.30 to 0.45 mm. Diameter of head without inflated 

 cuticula, 17 to 23 [jl; with inflated cuticula, up to 45 ]x.. Three males 

 only available for study. 



Hahitat. — Small intestine of sheep. 



Distribution. — Michigan. 



Type specimens. — U.S.N.M. Helminthological Collections, No. 

 18988, collected from the small intestine of a sheep by W. L. Chand- 

 ler at East Lansing, Michigan, 1919. 



NEMATODIRUS NEOTOMA Hall, 1916. 



1912. Nematodirus specie.s Hali,, 1912, p. 351. 



1916. Nematodirus neotoma Haij., 1916, pp. 136-138, tigs. 172-180 (type 



specimens, U.S.N.M.Helin.Coll., No. 16134, from Neotoma cinerea 



rupicola, Colorado). 



Specific diagnosis. — Nematodirus: Medium-sized species. Male, 

 8 to 11 mm. long, with a maximum diameter of 135 [i. Bursa 

 with stout rays. Dorsal lobes set off by wide notch from lateral 

 lobes and united with each other by a membrane showing only a 

 shallow median indentation. Bosses numerous and very small. 

 Bursal membrane marked with indistinct striations. Spicules, 3 to 

 3.4 mm. long, ending in a blunt point not provided with a distinct 

 terminal piece. Esophagus, 335 to 500 [x long. Female, 18 to 22 mm. 

 long, with position of vulva as in ^V. fllicollis. Anus about 120 jx 

 from posterior end. Ovijectors longer and less muscular than in N. 

 flicoUis. P:ggs 145 to 190 [a by 80 to 90 ix. 



Hahitat. — Small intestine and stomach of rodents of the genus 

 Neotomxi. 



Distribution. — Colora do. 



NEMATODIRUS MAURITANICUS Maupas and Senrat, 1912. 

 1912. Nematodirus inauritanicus Maupas and Seukat, 1912, pp. 628-632, 

 figs. 1-10 (from .small inte.stine of dromedary, Ghardaia, North 

 Africa). 



Specific diagnosis. — Nematodirus: Species large. Male, 13 to 15 

 mm. long, with maximum diameter of 167 to 170 jx. Dorsal lobes of 

 bursa set off from lateral lobes by deep indentations and united*svith 

 each other as in N, neotoma. Spicules, 4.5 to 5.5 mm. long, provided 

 with a sharply pointed terminal piece in the shape of a parallelo- 

 gram. Length of esophagus, 575 to 610 [x. Female. 21 to 24 mm. 

 long, with vulva between middle and posterior third of body, and 



