322 ORDER ANAXONCHIA 



through a narrow vestibule. The cavity itself is very small, and a good deal 

 wider than it is high when the lips are closed. In fact, when the lips are closed 

 they appear to form a depression on the front of the head, so that their interior 

 margins actually rest on the dorsal tooth and on the base of the pharynx. The 

 pharynx actually continues to twice the depth indicated in the formula, though 

 when the mouth is closed this posterior portion appears to be very similar to 

 the lumen of the oesophagus. The oesophagus swells a little in the anterior 

 third, then diminishes almost imperceptibly, and finally swells toward the pos- 

 terior extremity where it is two-thirds as wide as the base of the neck. The 

 thick-walled intestine becomes at once two-thirds as wide as the body, and 

 expands so as soon to be three-fourths to four-fifths as wide as the body. Its 

 cross-section would probably present about eight cells. The elongated ventral 



7.4+ 15. "W" 92.3 >16 gland lies im- 



'%J '*"'' i;i 2 ' 6 ' ' " mediately be- 



8.1.^15. "-M 91.9 y . , hind the cardiac 



'&'*"* W^iV ' - constriction. 



The lateral fields are about one-third as wide 

 as the body, and are composed mainly of a 

 double row of very prominent ellipsoidal cells, 

 which in the females at least, may be most 

 clearly seen in the region of the neck. From 

 X750 the slightly raised vulva, the vagina leads 

 inward about half way across the body. The uteri are generally about one and 

 one-half times as long as the neck, and contain numerous developing eggs or 

 embryos. The ovaries are reflexed for a distance about twice as great as the 

 body-diameter, and contain a dozen or more ova arranged in several series. This 

 species is viviparous. Tail of the male is very much like that of the female, but 

 more arcuate. Its terminus has a diameter one-fifth as great as the diameter 

 of the base of the tail. The equidistant supplements are of unequal size, those 

 more distant from the anus being much the larger. The first is opposite the prox- 

 imal ends of the spicula and is very minute. It is visible mainly on account of 

 the refractive nature of the material of which it is composed. The second is 

 about twice as far from the anus as the first and of about the same size. The 

 third, which is three times as far from the anus as the first, is very much larger, 

 having a length half as great as the body-diameter; its internal walls are brown 

 and strongly lined and refractive. It is somewhat curved and passes inward 

 and forward; its proximal portion is slightly cephalated. The fourth of these 

 organs is more than four times as far from the anus as the first, and is more than 

 twice as long as the third, having a length approximately equal to the body- 

 diameter. Its internal walls are strongly cutinized, and it is a very prominent 

 feature, almost as much so as the spicula. Where it passes through the cuticle, 

 its point is curved backward; thence inward, it is somewhat sigmoid, enlarging 

 all the time, so that its proximal portion is about one-fifth as wide as the cor- 

 responding portion of the body. The slightly arcuate, rather uniform spicula 

 are somewhat longer than the anal body-diameter. Their proximal ends are not 

 distinctly cephalated. Parallel to the spicula, and extending inward from the 

 prominently raised anus for a distance three-fourths the length of the spicula, 

 are the accessory pieces, whose distal extremities are two to three times as wide 

 as the spicula, but which decrease in size internally. They are considerably 

 more prominent than the spicula. The ejaculatory duct is about half as wide 

 as the body. 



