MYOLAIMUS 



275 



to detect with the nema in profile, more easily when viewed dorso-ventrally. 

 Behind the anterior chamber of the pharynx, which in many respects resembles 

 that of Diplogaster, there is a muscular portion closely resembling the oesophagus 

 in size and structure, but which seems undoubtedly pharyngeal. This is indi- 

 cated in two ways; first, the lining is different from that of the portion of the 

 oesophagus immediately following it, and second, it behaves differently with 

 staining material, indicating that its muscular wall also is considerably different 

 in nature from that of the oesophagus. The dimensions given in the formulae 

 relate to the anterior or labial chamber. At the base of the anterior pharyngeal 

 chamber there appear to 



13.7 25.2 



A 3.9 



(Sflpft/m 



be minute cutinous pro- 

 cesses which perhaps may 

 function as onchia. It 

 would appear possible 



that all that portion of the pharynx in front of the folds ' 

 in its lining are capable of being opened out or everted. 

 From the pharynx the oesophagus is cylindrical to near' 

 the nerve-ring, where it diminishes rather suddenly in 

 diameter near the very faint vestiges (?) of a median 

 structure. The vestiges consist in internal modifications 

 of the oesophagus only. From the nerve-ring onward the 

 oesophageal tube is about two-fifths as wide as the corre- 

 sponding portion of the neck. It finally expands to form the elongated-ellip- 

 soidal cardiac bulb, which bears a more or less distinct cardia, and is separated 

 from the intestine by a shallow constriction. The cardiac valvular apparatus 

 appears to be comparatively simple. The intestine becomes at once four-fifths 

 as wide as the body. The intestinal walls are rather thick, and the cells are 

 packed with minute granules. The rectum is about twice as long as the anal 

 body diameter. The lateral fields appear to be half as wide as the body. 

 The tail of the female is conical to the acute terminus and presents the peculiarity 

 of diminishing in diameter very suddenly immediately behind the anus, the dimi- 

 nution taking place on the ventral side. The anal region is, therefore, conspic- 

 uous on this account, as well as on account of the fact that it is slightly depressed, 

 and again on account of the refractive nature of the lining of the comparatively 

 long and large rectum. The salient lips of the vulva are conspicuous, a property 

 that is increased by the refractive nature of the lining of the vagina, which extends 

 inward two-fifths the distance across the body. Tail of the male very different 

 from that of the female. There is a bursal membrane connected with the digi- 

 tate organs shown in Fig. 60. The specimens seen were molting, so that the exact 

 nature of the membrane, which is believed to connect these organs one with 

 another, has not been deciphered. It seems also certain, however, that the ante- 

 rior four are joined together by means of a ventrally submedian membrane 

 somewhat as in the case of the bursa in Rhabditis. The spicula are very weak 

 and poorly developed in the specimens thus far seen. They appear to be as 

 long as the tail, and are probably cephalated at their proximal ends by constric- 

 tion; but they are very difficult to discern, and it is possible that the appearances 

 are deceptive and that they are altogether absent. The testis extends forward 

 to near the posterior end of the neck and appears to be reflexed for a short dis- 

 tance, but this is somewhat uncertain. 



Habitat: Loamy soil, El Paso, Texas, U. S. A. Flemming to glycerine jelly. 

 Fig. 60. 



