NEMATODE GENUS PHYSALOPTERA. 1027 



the 4th pair is at the middle of the tail, and it divides the 

 distance from the last pair of pedunculated papilla? to the tip of 

 the tail in about the ratio of 1 : 2. 



The ventral surface of the bursa is ornamented with longi- 

 tudinal rows of tubei'cles extending slightly posterior to the last 

 pair of stalked papillse. 



The spicules are short, equal, and pointed ; the right, however, 

 has a slightly stouter base ; they are 275 /><, long, the left spicule 

 being 25 and the right 30 ju thick at its base. 



Hosts: Falco galUcus. Intestine. Museum, Vienna ; bottle 

 4439. 

 Falco penncdus. Stomach. Museum, Vienna ; bottle 

 4442. 



Discussion. — This material differs from Schneider's (1866), 

 von Linstow's (1877), and Seurat's (1914 c) descriptions of this 

 species in the nature of the teeth and in the arrangement of the 

 male bursal papillae ; these two characters are in keeping with 

 Ph. suhcdata Schn., 1866, and Fh. galinieri Seurat, 1914. As 

 the specimens examined consisted of the paratypes of Ph. alata, 

 it appears to me that the conception of the species has been 

 erroneous. Further, it would appear that Seurat's species Ph. 

 galinieri is either a synonym or a vai-iety of Ph. alata^ because 

 it agrees with Rudolphi's species in the nature of the teeth, the 

 arrangement of the male bursal papillae, the very posterior 

 position of the vulva, and the anterior direction of the vagiaa ; it 

 differs from Ph. alata in its relatively shorter oesophagus and in 

 its slightly longer and subequal spicules. 



Rudolphi described this species from three hosts in the Vienna 

 Museum, viz. Falco nisus, F. 2}eiin<:itus, and F. gallicus. I take 

 his specimens from the first-named host to be the types of this 

 species, and the material from the other two hosts to be the para- 

 types. 



An extracted description of Ph. galinieri Seurat is incluiled in 

 Part II. 



(8) Physalopteea betusa Rudolphi, 1819. (Text-figs. 11 & 12.) 

 Syn. 8piroj)tera retusa (Rud., 1819), Duj., 1845. 



I have been able to examine two lots of material of this species, 

 both having been collected from the Teguexin. The first lot 

 consisted of specimens deposited in the Vienna Museum (bottle 

 4497), and the second I collected from a Teguexin which died in 

 the Gardens of the London Zoological Society. Both sets of 

 material were in all respects identical. 



The cuticle is very finely striated transversely and, in addition, 

 shows a coarse irregular ringing. Anteriorly it is partly or 

 wholly reflected over the lips. 



The cervical papillae are inserted generally symmetrically on 

 either side, but sometimes one may be slightly more anterior to 

 the other; they are lodged a short distance behind the junction 



