440 JOUKNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 22, NO. 12 



not be seen. These striae are not altered on the lateral fields; there are no 

 longitudinal wings. The subcuticle, 99, usually contains multitudinous 

 pebbly, i.e. roundish or slightly elongate, yellowish pigment granules, 34, 

 82, 95, one to two microns across, "paved" in longitudinal bands of variable 

 width; two broad lateral bands, one on each side of the body, about one- 

 third as wide as the nema and having narrower submedian bands on each side; 

 and three narrow ventral bands as well as even narrower dorsal bands. These 

 bands are better seen after staining over night in seawater-methylene-blue, 

 which may not only stain them but bring out the fact that the granules along 

 the edges of the two main lateral bands are of a somewhat different nature 

 from the rest. Longitudinal striations in the subcuticle, clue to the attach- 

 ment of the musculature, 4, 16, 77, are faintly visible at high magnification in 

 most regions of the body, especially the more translucent parts. The body 

 wall, including the cuticle, is about six microns thick. 



Ten widely spreading cephalic setae, 26, are arranged on the lateral surface 

 of the lip region in the usual way, i.e. a pair on each submedian line and one on 

 each lateral line; the longest of these are one-fourth as long as the correspond- 

 ing portion of the head is wide, the shorter member of each submedian pair 

 being about three-fourths as long as the longer. The members of the sub- 

 median pairs grow so close together as sometimes to appear as one. These 

 subcylindroid setae are nearly straight and are blunt at the end, where they 

 seem more or less open, not closed, indicating, probably, that they may also 

 be connected with some sense in addition to that of touch. There are a few 

 scattered subcephalic setae near the head, of nearly the same length (ten to 

 twelve microns) as the cephalic setae, but more slender. On the neck and on 

 the body there are also a few scattered setae, very inconspicuous and seldom 

 seen. There are also a few very short, very inconspicuous setae on the tail, 

 especially toward its extremity and on the spinneret, 24, 74. There are no 

 cuticular pores. 



The neck and head. The head and neck occupy the anterior 11 to 13 per 

 cent of the body, i.e. the part in front of the prominent constriction, 13, be- 

 tween the nearly colorless oesophagus, 12, 36, and the darker intestine, 83, 94. 

 The slightly conoid neck ends in a subtruncate continuous head, the frontal 

 mouth opening in which is not depressed. In front the pharynx, 31, 48, 57, 

 is arched over by the six distinct and separate, flat and thin, fairly well 

 developed, mobile lips, 28, 49, which are not set off by constriction or in any 

 other way. As a rule the lips are not readily counted except when seen from 

 in front. Toward the margin of the head there is a circlet of six, innervated, 

 very minute and inconspicuous, forward-facing sensory papillae, 29, 45, one on 

 each lip. This circlet is about two-thirds as wide as the front of the head. 

 These papillae also are rather difficult to see except from in front, 45. The 

 rather simple subregular pharynx, 31, 35, 48, 57, about forty by twenty-three 

 microns, is somewhat cylindroid anteriorly and vaguely conoid posteriorly. 

 The posterior "chamber," 35, sixteen by nine microns, supports the three 

 acute onchia, 25, 33, 53, the forward pointing projection of the largest of which 

 is very readily seen. Taken as a whole the pharyngeal cavity might be 

 described as somewhat convex-conoid. Its refractive, cuticularized wall is 

 nearly two microns thick. 



Its armature consists of three unequal, conoid, perforated, pointed onchia, 

 one dorsal, 25, two ventrally submedian, 33, 53. Of these the grooved left 

 ventral submedian, 27, 53, is much the largest, and reaches two-thirds the dis- 

 tance to the lips. The other two, e.g. 33, 25, nearly equal in size, reach only 

 about halfway to the lips. Each onchium is the outlet of a branched and 



