2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 78 



convoluted filaments on the spicules, a feature ^yhich, so far as I am 

 aware, has not been described in any other nematode. Railliet, 

 Henry, and Bauche suggested that Bourgelatia belonged with the 

 Oesophagostominae, in spite of the absence of a ventral cervical 

 groove, but Baylis and Daubney (1926) placed it with the Tricho- 

 neminae, since, as they point out, the ventral groove is the main dis- 

 tinguishing feature of the Oesophagostominae. Yorke and Maple- 

 stone (192G) likewise placed Bourgelatia with the Trichoneminae. 

 Bourgeloti&kles^ on the other hand, although it resembles Bourge- 

 latia in many waj's, should probably be included with the Oesopha- 

 gostominae, which it resembles both in the presence of a cervical 

 groove and in the bursal formula. In this case the cervical groove 

 completely encircles the body, however, and is not merely ventral. 

 In my opinion the separation of the Trichoneminae and Oesopha- 

 gostominae into separate subfamilies is of doubtful validity, but if 

 the subfamily Oesophagostominae is to stand its definition should 

 be changed so that the cervical groove is not limited to the ventral 

 side. 



BOURGELATIOmES TRAGULI, new species 



Figures 2 and 3 



Specific Diagnosis. — Bourgelatioides : Coarse cylindrical worms, 

 thickest near the middle, tapering gradually anteriorly from the 

 middle, but tapering very little posteriorly except near the end of 

 the body. Cuticle with very fine striations, more distinct in the 

 female than in the male. Mouth capsule shallow, cylindrical, with 

 heavily chitinized walls, and divided by an inner crown of 20 to 

 25 small leaflets into an anterior and posterior portion ; anterior por- 

 tion of capsule with four large papillae in the wall. Head about 

 67/x in diameter at the level of the posterior end of the buccal capsule. 

 The groove and overlying flap which separate the head from the 

 rest of the body are about 200^ from anterior end of body. Esoph- 

 agus club shaped, about 550/x long. 



Male 11.3 mm. long, with a maximum diameter of 420;li, tapering 

 in the anterior 2 mm. and very gradually in the posterior 31/2 nim. 

 of the body length. Bursa about as long as broad, about 240ja in 

 either direction. Dorsal ray forked for about half its length, each 

 fork again bifurcated for about half its length ; externodorsals very 

 large and thick, extending into the lateral lobes. Lateral rays all 

 about equal in size, the posterolateral and mediolateral closely ap- 

 proximated and fused basally ; ventral rays slightly smaller than the 

 laterals, and closely approximated to each other, but split to the 

 common base; all rays reach the edge of the bursal membrane. 

 Spicules 655/* long, exclusive of the terminal filaments, about 24;u 



