52 PROCEEDINGS OF THE NATIONAL MUSEUM vol.81 



from America. The following account contains the description of a 

 second species, which is parasitic in the three-toed box turtle : 



ATRACTIS CAROLINAE, new species 



Plate 4, Figure 7 



Specific diagnosis. — Atractis: A very small, white, parasitic worm. 

 Body cylindrical, and tapering at each end. Tail of both sexes 

 sharply pointed. Cuticular striations faint and l/x to 2jl(, apart. 

 Mouth surrounded by six lips, each of which bears two papillalike 

 protuberances at the distal end and two more just proximal to them. 

 The esophagus is divided into two equal parts and ends in the usual 

 bulb. 



Male: Length 2.3 to 2.85 mm; width %2>fx to 80/i,. The esophagus is 

 0.48 to 0.55 mm long, and the bulb measures 75/1, to 80/i long by 

 63yu, to 75/i, wide. The nerve ring and excretory pore are 0.35 to 0.38 

 and 0.375 to 0.415 mm, respectively, from the anterior end. The tail 

 is 0.33 mm long. The spicules are very unequal, the long one being 

 0.333 to 0.34 mm long, and the short one only 75fi to 84ju, long. 

 The long spicule is well cutinized, conspicuously cross-striated, and 

 about 10/i, wide. The short spicule is but slightly cutinized and un- 

 marked. The gubernaculum is 60/i, to 80/* long and notched near the 

 anterior end. There is a row of five papillae, placed close together 

 on each side of the anus. There may be four more pairs of postanal 

 papillae, but they are not always present. 



Female : Length 2.5 to 2.95 mm ; width about 85/*. Esophagus 0.47 

 to 0.57 mm long, its bulb measuring 1\\t. to 80)li long by 63/i to 71/* 

 wide. The nerve ring and the excretory pore are 0.25 to 0.3 and 

 0.35 mm, respectively, from the anterior end. The vulva is only 

 63/i to 85/x. in front of the anus. The tail is 0.5 to 0.55 mm long. 



Host. — Ten'apene Carolina triu/nguis. 



Habitat. — Rectum. 



Locality. — Houston, Tex. 



Type specimens.— \].^:^M.. Helm. Coll. No. 31702; paratypes, 

 No. 31703. 



Remarks. — These nematodes were always present in large numbers 

 in the rectum of the host, but they are so small that at first they 

 were passed over as larval forms of other nematodes present in the 

 same host. Possibly other investigators have encountered this same 

 form and have disregarded it for the same reason. This species may 

 easily be separated from Leidy's A. opeatura by size, structure of 

 lips, size of spicules, and number of papillae. 



