324 ORDER ANAXONCHIA 



these structures are so very peculiar as to suggest abnormality, but as there is 

 no evidence of any disease or malformation in the single, very transparent 

 specimen examined, it seems best to regard it as the normal form of a very 

 exceptional species. 

 Habitat: Salt River, Jamaica, in six inches of water. Fig. 102, p. 323. 



1.8 10. 16. Y 88. 

 ......... .^ .g 



103. Amphispira rotundicephala n. sp. * *? 1i? *? 5- Contour 

 plain, or exceedingly finely crenate. Apparently there are very faint subce- 

 phalic setae near the base of the "cuirasse." At the mouth opening of the single 

 specimen examined there are three punctate spherical elements, as shown in the 

 illustration. The significance of these remains problematical; while they may 

 possibly be fixation products, such a supposition is doubtful. Neck conoid. 

 The oesophagus retains the same diameter until it expands to form the flattish- 

 pyriform cardiac bulb, which has a faint valve one-third as wide as itself. There 

 appears to be an almost imperceptible break in the musculature near the middle 

 of the oesophagus, and a corresponding very slight swelling. The thick-walled 

 intestine has a faint lumen and soon becomes one-half as wide as the correspond- 



jj ing portion of the body. Its cross-section pre- 

 sents few cells. From the apparently contin- 

 uous anus the prominent rectum extends a 

 distance equal to the anal body-diameter. The 

 scattered to rather numerous, spherical gran- 

 ules found in the cells of the intestine are of 

 variable size, the largest being one-thirty- 

 sixth as wide as the body. Tail arcuate, co- 

 X 750 noid, ending in a spinneret one-third as wide as 

 its base. The broadly truncate caudal glands are located opposite to and behind 

 the anus in the anterior third of the tail. The lateral fields are one-third as 

 wide as the body. What appears to be the renette cell is located about three 

 body-widths behind the neck; it is one-third as long as the body is wide and one- 

 half as wide as long. The location of the excretory pore remains unknown. 

 Nerve-ring oblique. From the location of the rudimentary sexual organs in the 

 single young specimen seen it seems probable that they will develop to be double 

 and symmetrically reflexed. 



Habitat: Soil, Arlington Farm, opposite the District of Columbia, U. S. A. 

 Flemming to glycerine jelly. This species almost seems out of place in the 

 habitat in which it was discovered, as it is most closely related to marine forms. 

 .Fig. 103. 



104. Micromicron cephalatum n. sp. 2 - 8 3-7 %7 3.8 '"> V ' " Neck short, 

 cylindroid. There seems little doubt that the mouth cavity is armed with a 

 single, dorsal tooth, which can be placed so closely against the dorsal wall of the 

 pharynx as to be difficult of detection, although the tooth itself is of considerable 

 magnitude. It appears to have an acute apex, located opposite to or a little 

 behind the labial constriction. Oesophagus cylindroid, ending behind in a pro- 

 late or pyriform cardiac bulb four-fifths as wide as the base of the neck. Cardia 

 faint. The intestine, which joins the middle of the posterior surface of the 

 cardiac bulb, is at first about one-third as wide as the neck. It widens out grad- 

 ually so as to become about half as wide as the body, and its cross-section would 

 appear to be composed of about six to eight cells containing yellowish granules 

 of rather uniform size. The lateral fields are about one-fourth as wide as the 



