NO. 1864. 



TWO NEW PARASITIC NEMATODES— RANSOM. 



367 



spur projecting dorsally. Anterior of the ventral beak a small hook, 

 and in front of the latter a series of two or three small projections, the 

 ventral surface of the distal portion of the spicules for a distance of 

 about 50 /I, thus having a hooked, barbed, and roughened appearance. 

 The ventral surface of the right spicule is 

 smooth. Tip of the right spicule smaller than 

 that of the left, with a small flattened caplike 

 enlargement projecting dorsally and ventrally 

 as very small pointed processes, and laterally 

 as a very small ridge. Gubernaculum (fig. 5) 

 about 100 ,« X 35 fx in length and breadth re- 

 spectively, similar in color to 

 the spicules, with an oval body 

 and a short pointed process 

 posteriorly and a longer proc- 

 ess anteriorly. 



Female, 5.8 to 7 mm. long 

 by 90 to 120 ;« in diameter at 

 the vulva. Anus 65 to 90 /i 

 from the tip of the tail. Pos- 

 terior end of the body (fig. 6) 

 is commonly rather abruptly 

 though slightly diminished 

 in size a short distance in 

 front of the anus, then tapers 

 gradually to the tip of the 

 tail, or beginning some dis- 

 tance in front of the anus 

 may taper gradually to the tip. Tail straight. 



Vulva (fig. 7) 850 /t to 1 mm. from the tip of the 

 tail, elongated diagonally, 50 to 60 /z long with in- 

 conspicuous lips. Combined length of muscular por- 

 tions of the ovijectors 450 to 560 /x. Eggs 60 to 70 /x 

 long by 30 to 36 p. wide, in 8 to 32 celled stage 

 when deposited. 



Host. — Rabbit (Lepus sylvaticus). 

 Location. — Small intestine. 

 Locality collected. — ^Bowie, Maryland. 

 Type-specimens. — Bureau of Animal Industry Hel- 

 minthological collection. Cat. No. 15968, U.S.N.M., 

 collected May 31, 1911. 



This nematode has been found almost constantly 

 present in wild rabbits in the vicinity of Bowie, 

 Maryland. The only other known species parasitic in rabbits with 

 wliich it is likely to be confused is TricJiostrongylus retortseformis, 

 and from this it may readily be distinguished by the wide differences 



lOOyuL 



Fig. 6.— Trichostrongylus 

 calcaratus. posterior 

 end of body of female 

 viewed from left side. 



lOO/Ji. 



Fig. 7. — Trichostron- 

 gylus CALCARATUS. 



Region of vulva of 

 female viewed from 

 right side. 



