70 NORTH AMERICAN 



The striae are more or less interrupted on the lateral fields by two wings, 

 or by a single wing indicated by two longitudinal lines. The width of the 

 wing near the middle of the body is about equivalent to the width of four 

 of the annules of the cuticle. Toward the tail end the width of the inter- 

 rupted space is about equivalent to the width of three of the annules, and 

 near the middle of the neck the width is also about equivalent to that of 

 three of the corresponding annules. Through the middle of the lateral space 

 on which the annules are interrupted there passes a longitudinal refractive 

 line. The posterior portion of the neck is cylindroid; the anterior half 

 conoid to the head, which is not set off in any way. The lips are arranged 

 in two series: an outer series of six two-parted lips, and an inner series of 

 three obscurely two-parted projecting flaps, each armed at the anterior 

 rounded corners with short, arcuate, tapering, acute, forward-pointing 

 bristles. Each of the two parts of the six outer lips or appendages is con- 

 oid and acute, and the spaces separating them are much narrower than those 

 separating the lips themselves. At the base of each of the lateral two-parted 

 lips there is a transverse mark, which may possibly be the outer expression 

 of the amphid. This marking is very minute and about four times as wide 

 as it is long, and is placed transversely on the base of the lip, iust in front 

 of the foremost cervical annule. It spans about one-sixth of the width of the 

 head at this point. The three inner appendages, which may more properly 

 be termed the lips, are about as long as they are wide, and seem to be flex- 

 ible. They rather closely surround the mouth opening. Each is half as 

 wide again at its free extremity as it is at the base, and the total length is 

 about equal to one-fourth of the diameter of the front of the head. The 

 setae with which these lips or flaps are armed are about two-thirds as long 

 as the flaps themselves. The rather obscure, narrow, cylindroid pharynx 

 is about as long as the base of the head is wide, and its lumen is hardly 

 wider than the thickness of the cuticle. The oesophagus surrounds the 

 pharynx, but is narrower in this region than it is immediately behind the 

 pharynx. Behind the pharynx it commences as a tube about three-fifths as 

 wide as the base of the head, and continues to have about the same diameter 

 until after it passes through the nerve-ring. It does increase a trifle in 

 diameter, however, so that at the nerve-ring it is about one-half as wide as 

 the corresponding portion of the neck. Some distance behind the nerve-ring, 

 namely, at a distance about equal to one and one-half diameters of the neck, 

 there is a slight break in the musculature of the oesophagus. Behind this 

 break the oesophagus begins to taper very gradually and continues to de- 

 crease in diameter until it finally expands to form the somewhat ellipsoidal or 

 pyriform cardiac bulb, which is about two-thirds as wide as the base of the 

 neck, and contains a distinct, rather simple, triple, chitinized valvular appa- 

 ratus. That portion of the oesophagus immediately in front of the cardiac 

 bulb has a diameter about one-fourth as great as that of the corresponding 

 portion of the neck. The lining of the oesophagus can be seen throughout its 

 length, and is a fairly distinct feature. The intestine which at first is thin- 



