1922.] H. A. Baylis and R. Daubney : Parasitic Nematodes. 309 



Distance from ant. end to end of oesoph (incl. bulb) 

 ., ,, nerve-ring 



,, ., excretory pore 



Length of pharynx 

 Oesophageal bulb, length 



., ,, greatest diameter 



Spicules, length 



Vulva, distance from posterior end 

 Caudal papillae, 9 , distance from tip of tail 

 Ova, measurements 



Falcaustra kachugae, according to Stewart's (1914") description, seems to differ 

 notably from F. stewarti in its much smaller dimensions ; but as the type-material 

 consisted only of a single female, which may not have been mature, the question of 

 identity must be left open. 



In view of the several new species just described, it is necessary to revise our 

 conception of the generic diagnosis of Falcaustra. Diagnoses have been attempted 

 by Seurat (1918) and by Baylis (1920 b), but both require some alteration. The 

 following is an attempt at a fresh generic characterization. 



d 



? 



mm. 



m m . 



2-6-2-8 



2-7-28 



0.56 



0-6 



1-9 



20 



01 



o-i 



0-55-0-58 



0-6 



0-35 



04 



054-0-56 



.... 



.... 



8-5-8-8 



.... 



20 



. » . . 



0-15x0-0875 



Falcaustra, Lane, 1915. 



Ascaroidea : Kathlanidae : ' Meromyarian. Body usually stout, tapering at each end. Lateral 

 fields wide. No lateral alae. Mouth with three lips, each bearing two outer and two inner papillae; 

 the pulp of each outer papilla sends a branch to one of the inner papillae, and is thus Y-shaped. 

 Buccal cavity short, surrounded by a continuous ring % of thickened cuticle. Muscular oesophagus 

 divided into a short anterior portion, or pharynx, and a long posterior portion, the latter ending in a 

 well-marked bulb which is constricted in the middle so as to take the form of two more or less distinct 

 swellings connected by a narrower neck. The oesophagus, with the exception of the bulb, is usually 

 considerably coloured with a reddish-brown pigment, and there are generally special masses of this 

 pigment in the region of the nerve-ring. Excretory pore towards the posterior end of the oesophagus. 

 Tail in both sexes tapering and pointed. Caudal end of male without alae, and provided with ten or 

 more pairs of papillae (of which three pairs are constantly preanal). and an unpaired, median preclo- 

 acal papilla. Of the postanal papillae two pairs are constantly lateral. Preanal caudal muscles well- 

 developed, sometimes aggregated into one or several fan -shaped groups to form sucker-like organs. 

 Spicules equal, sickle-shaped, broad dorso-ventrally and compressed laterally, each having the appear- 

 ance of a spicule within a spicule. An accessor}' piece usually present, sometimes imperfectly chitinized 

 or even absent. Vulva towards posterior third of body. Vagina runs forward and gives off two 

 opposed uteri, each of which doubles upon itself in a number of longitudinally-disposed U-shaped 

 loops in the anterior or posterior region of the body respectively. Each ovary forms a loop in the 



1 Travassos (1918) established this family to include the genera Kathlania, Tonaudia. Falcaustra and Florencioia. 

 It is the family Pseud o-heterakidae, Travassos, 1917, renamed and reconstituted. No family diagnosis however, seems 

 to have been attempted. In our opinion the genus Cruzia, Travassos, 1917, should also be included in the family, and 

 not referred to a separate family Cruzidae, as Travassos has proposed. We have also to add a further new genus, 

 closely allied to Falcaustra (see below, p. 310). 



? Seurat (1918) in his diagnosis of the genus, speaks of the buccal cavity being " encadrée dans sa région moyenne 

 par trois plaques chitineuses." If such a structure exists in F. lambdiensis, the form studied by him, it would appear 

 to approach our genus Zanclophorus (see below, p. 310), though the rest of its characters seem to be those of Falcaustra. 



