Miscellaneous. 315 



Hab. This species is found in numbers of from three up to fifty or 

 more, of various ages and sizes, pretty constantly in the small intes- 

 tine of Julus marginatus, Say. The males are found in the propor- 

 tion of about one in eight. 



Aorurus, a new genus o/Nematoidece. — Body cylindrical, strongly 

 annulated, with a tail nearly as long as the body, straight or nearly 

 so, inflexible, spiculate, ensiform, shining, and pointed. Mouth un- 

 armed. Female generative aperture near the middle of the body. 



Remarks. — This genus is divisible, by several well-marked cha- 

 racters, into two distinct subgenera. 



1st subgenus. Streptostoma. — Body cylindrical, very strongly 

 marked with broad annuli. Mouth moderately large, round, bordered 

 by a collar (formed by the second aimulus projecting beyond the 

 general outline of the body). (Esophagus divided into two distinct 

 pyriform muscular bulbs, with a small intermediate rounded bulb. 

 Tail four-fifths the length of the body. 



Streptostoma agile. Female. — Body larviform, cylindrical, nar- 

 rowed anteriorly and posteriorly, opalescent white, divided into from 

 sixty-one to eighty-eight broad annulations, of which there are 

 twenty-one from the mouth to the commencement of the ventriculus. 

 Tail very straight, occasionally slightly sigmoid, or bent at the point, 

 narrow and sharply pointed, inflexible and brittle. Mouth moderately 

 large, round, projecting ; pharynx almost null ; oesophagus consisting 

 of three bulbs : the first elongated pyriform, strongly muscular, mea- 

 suring 1-19/th in. long by l-319th in. broad; second bulb small, 

 rounded, muscular, 1 -882nd in. long by 1 -882nd in. broad ; third, or 

 true oesophageal bulb, pyriform, l-294th in. long by l-312th in. 

 broad. Ventriculus dilated at commencement to nearly the diameter 

 of the body, afterwards straight and cylindrical to near its termina- 

 tion, where it is slightly dilated. Rectum elongated, pyriform. 

 Generative aperture situated about twenty-four rings above the anal 

 aperture, which latter is placed between the last two annuli of the 

 body. Ovary double ; ova 1 -333rd in. long by 1 -400th in. broad. 



Length of body from l-13th to 1-1 1th inch ; breadth at commence- 

 ment of ventriculus 1-1 18th. inch; at middle of body l-97th inch. 

 Tail from 1-1 6th to 1-1 5th inch long, by 1 -888th in. broad at its 

 middle. 



2nd subgenus. Thelastoma. — Body cylindrical, attenuated an- 

 teriorly, strongly marked with moderately broad annuli. Mouth 

 small, opening at the extremity of a small papilla. (Esophagus 

 divided into two distinct portions, the first long and cylindrical, the 

 second constituting the true oesophageal bulb. Tail more than half 

 the length of the body. 



Thelastoma attenuatum. Female. — Body attenuated anteriorly to 

 commencement of the ventriculus, opalescent white, divided into from 

 140 to 160 annulations, of which there are from fifty-two to fifty- 

 seven from the mouth to the commencement of the ventriculus. 

 Tail very straight, or very slightly curved or bent, slender, inflexible 

 and brittle, and sharply pointed. Mouth always projected, small, 

 surmounting a small papillary elevation formed by the first annulus 



