No. 2386. TWO NEW GENERA OF NEMATODES— HALL. 545 



the direction of the spicules; they also support the cloacal wall and 

 aperture, the spicules when these are extruded, and the genital 

 cone in some cases; a platelike gubernaculum projecting from the 

 dorsal wall of the cloaca may also aid in separating the spicules to 

 form a suitable channel for the passage of the spermatozoa. Appar- 

 ently the term gubernaculum should be restricted to the more or less 

 longitudinal structure in the dorsal wall of the cloaca toward the 

 anterior end, and the term telamon used for the supporting structure 

 of variable form near the cloacal aperture. 



The study of the telamon in the genus Hyostrongylus naturally led 

 to an examination of other nematodes to ascertain if this structure 

 was commonly present. A closely related worm, Omithostrongylus 

 quadriradiatus (Stevenson, 1904), Travassos, 1914, was first con- 

 sidered, since H. rubidus and 0. quadriradiatus were both originally 

 described from this laboratory, the Zoological Division 

 of the Bureau of Animal Industry, with a description 

 and figure of a peculiar structure in the cloaca. Ex- 

 amination showed that the star-shaped structure (fig. 2) 

 figured by Stevenson is a telamon corresponding in 

 its general location and evident function with the 

 telamon in H. rubidus. An examination of species of 

 the trichostrongyle genera Cooperia, Ostertagia, Haemon- 

 chus, Graphidium, and Citellinema shows what are 

 apparently telamons in these genera, indicating that the F 

 telamon will be found generally present in the Tri- strongylus 

 chostrongylidae. What appears to be a telamon is tus^telamon 

 present among the Strongylidae in the genera Bustomum x 470. from 

 and Oesophagostomum. Among the Metastrongylidae 19 o 4 EVEN 

 it appears likely that what has been called the unpaired 

 accessory structure in Synthetocaulus pulmonalis (—Synthetocaulus 

 commutatus) must be regarded as a gubernaculum, and what have 

 been called the paired accessory structures must be regarded as the 

 elements of a telamon. The chitinous arc in which the body termi- 

 nates in the genus Synthetocaulus may also prove to be an element of 

 the telamon. An examination of a number of published figures of 

 male nematodes indicates that what is apparently a telamon has been 

 figured by various authors, sometimes without explanatory labeling 

 and sometimes as a gubernaculum or part of the spicules. Outside of 

 the Strongyloidea this structure appears to be present in some form in 

 the Oxyuroida and perhaps in the Spiruroidea and Filarioidea. It 

 appears to be best developed in forms having comparatively short 

 spicules and poorly developed in forms having long linear spicules, 

 so far as I have examined them. In its simplest form the telamon 

 seems to be a ring-shaped structure, complete or incomplete, surround- 

 ing the cloacal aperture. This elementary form is modified by the 

 27177— 21— Proc.N.M. vol.59 35 



