ANGUILLULIDJE FROM TROPICAL ORCHIDS. 87 



of the neck. The very small, circular lateral organs are 

 situated immediately behind the lip-region; their diameter 

 is only 1*5 /*. The chitinous pharynx is 25*5 — 27 //. long 

 from the mouth to its posterior end, and this length 

 measures from one-ninth to one-eighth of the distance 

 between the mouth and the commencement of the intes- 

 tine. The two chitinous lines, which are the longitudinal 

 optical section of the pharynx-wall, run parallel; the 

 pharynx is wide, so that its transverse diameter measures 

 one-fifth of its length. About in the middle it is sur- 

 rounded by a very thin, circular, chitinous band, and at 

 its posterior extremity it presents the ordinary constriction. 

 The oesophagus (PI. IV, fig. 3) has the same form as in 

 many other species of this genus, as e.g., in Bhabd. brevi- 

 spina, Biitschlii, curvicaudata, &c. The foremost portion, 

 which has a moderate width, leads about in the middle to 

 the ellipsoidal median bulb, which afterwards gradually 

 narrows to terminate with the sharply separated off 

 posterior bulb, which is nearly spherical. The median 

 bulb is about one and-a-half times as long as it is broad, 

 and the narrow portion of the oesophagus between the two 

 bulbs appears nearly six times as long as it is broad. 

 The posterior bulb, the valvular apparatus of which is 

 well developed, occupies one-sixth of the whole length of 

 the oesophagus, the pharynx included. The wall of the 

 intestine has the usual structure. I will only remark 

 that the rectum of the female is rather long, measuring 

 36 /*, accordingly still somewhat longer than the tail. 

 The nerve-ring is seen just behind the median bulb. 

 The ventral excretory pore, situated just behind the 

 nerve-ring, lies on a papillary prominence of the cuticula; 

 the excretory duct, when it comes opposite the pore, makes 

 first a little curve forward, and then, before terminating, 

 presents a small dilatation (PI. V, fig. 3 b). 



