NEURELLA, ZYGONEMELLA . 247 



ing forward; probably the renette cell. Excretory pore unknown. Nerve-ring 

 oblique, accompanied by distinct cells arranged in groups. 



Habitat: "Sea-grass," shoal, two miles off,' Key West, Florida, U. S. A. Sub- 

 limate to balsam. The view of the tail of the female was slightly foreshortened' 

 the formula must be interpreted accordingly. Fig. 25, p. 246. 



^.4_ _ _7_.3_ J3.6 -^t-" _ <&.&_ > 1 2 



26. Zygonemella striata n. sp. 3.,i 4.1 4.6" 5.3^3.6 " I n addition to the 

 cephalic setae, scattered on the anterior part of the neck, there are a consider- 

 able number of other similar setae, some of which are longer than those near the 

 margin of the head. Lips three, massive but low, faintly bi-lobed; within these 

 there is a rather broad inner mouth consisting of three soft, low, flat lobes, which 

 appear to be extensions of the tissue of the oesophagus. These latter present 

 faint refractive elements, the expression of minute foldings of the lip tissues, 

 that make possible the great expansion necessary for the deglutition of the rela- 

 tively large diatoms constituting the food. In appearance the pharynx closely 

 resembles the lumen of the oesophagus. It would, in fact, be indefinable, were it 

 not for the pharyngeal swelling which is half as wide as the head, that is to say, 

 a very little wider than the remainder of the oesophagus. Immediately behind 

 the pharyngeal swelling the oesophagus diminishes gradually, so that where it 

 passes through the nerve-ring it is about set ft (6?) .. 

 two-fifths as wide as the neck; thence 



onward it is cylindroid. The lining of the / lfl} -^ .( 

 oesophagus is a conspicuous feature 

 throughout its length. The tubular cardia 

 is prominent, about one-fourth as wide as 

 the base of the neck, and about one and 

 one-half times as wide as long. The intes- X 75( 

 tine is almost at once fully half as wide as the body and is separated from the 

 oesophagus by a broad and deep constriction. Its cross-section probably com- 

 prises only two cells. The cells contain scattered granules of small size and 

 rather uniform diameter. The lateral fields, about one-fourth as wide as the 

 body, contain cells packed with fine uniform granules. Renette unknown. The 

 tail of the male is conoid in such fashion that at the beginning of the final third 

 it has a diameter about equal to the width of two of the corresponding annules; 

 thence onward it is very nearly cylindrical. The anus is slightly raised, its 

 posterior lip elevated. The caudal glands are packed in a tandem series opposite 

 the anus and occupy a space somewhat longer than the anal body-diameter; 

 their ducts are narrow. Spicula acute, not quite as long as the anal body-diam- 

 eter; their width about equal to the width of one of the adjacent annules. They 

 taper in the distal fourths to slender, acute points. The posterior testis is only 

 about half as long as the anterior. Ten unicellular glands are a prominent fea- 

 ture of the anatomy of the male. (1) A pair of clavate glands immediately 

 behind the blind end of the reflexed posterior testis. Each of these glands has a 

 length nearly equal to that of the adjacent body-diameter, and empties through 

 a duct extending backward. The ducts have a width somewhat greater than 

 that of one of the adjacent annules. (2) Just behind the pair of glands already 

 mentioned is a second clavate pair of larger size and very similar; these are about 

 half as wide as the body and somewhat longer than the body is wide, and the 

 ducts extending backward from them have a width greater than that of two of 

 the adjacent annules. (3) Behind the second pair of glands there are six small, 

 pyriform glands, i.e., a set of three on each side of the body, arranged longitudi- 

 nally close together, but having separate ducts, also extending backward. It 



