ENTOZOA. G5 



bicular mouth, but differs from it in the capillary tenuity of the anterior 

 part of the body, and in the form of the sheath or preputial covering 

 of the male spiculum. The species in question, the 

 Trichocephalus dispar Rud. (^Jig. 29.) is of small size, 

 and the male is rather less than the female. It occurs 



a 



Trichocephalus most commonlv in the caecum and colon, more rarely 



dispar. Nat. size. '' . ,, . . p 



in the small intestmes. Occasionally it is found loose 

 in the abdominal cavity, having perforated the coats of the intes- 

 tine. The capillary portion of this species makes about two-thirds 

 of its entire length ; it is transversely striated, and contains a 

 straight intestinal canal ; the head («) is acute, with a small simple 

 terminal mouth. The thick part of the body is spirally convoluted 

 on the same plane, and exhibits more plainly the dilated intestine ; 

 it terminates in an obtuse anal extremity, from the inner side of 

 which project the intromittent spiculum and its sheath. 



The species called Spiroptera Homhiis was founded by Rudolphi 

 on some small nematoid worms expelled, with many larger elongated 

 bodies of a solid texture, and with granular corpuscles, from the urinary 

 bladder of a woman, whose case has been described by Mr. Lawrence 

 in the Medico-chirurgical Transactions.* The Spiroptera varies 

 from eight to ten lines in length ; the head truncated, mouth or- 

 bicular, with one or two papillae, body attenuated at both extremities ; 

 the tail in the female, thicker, and with a short obtuse apex ; that of 

 the male more slender, and emitting a small tubulus ; a dermal aliform 

 production near the same extremity determined the worms in question 

 to belong to the genus Spiroptera.^ 



The most formidable, but, happily, the rarest of the Nematoid 

 parasites of man, also infests the urinary system, but is developed in the 

 kidney, where it has attained the length of three feet, with a diameter 

 of half an inch ; occasioning supi3uration and destructive absorption 

 of that important glandular organ. 



The male Strongylus gigas {Jig. 30.) is less than the female, and is 

 slightly attenuated at both extremities. The head («) is obtuse, the 

 mouth orbicular, and surrounded by six hemispherical papillae ; the 

 body is slightly marked with circular striae, and with two longitu- 

 dinal impressions ; the tail is incurved in the male, and terminated 

 by a dilated pouch or bursay from the base of which the single intro- 

 mittent spiculum {g) projects. In the female the caudal extremity is 

 less attenuated and straighter, with the anus a little below the 

 apex; the vulva is situated at a short distance from the anterior 

 extremity. 



* Vol. ii. p. SS5. f Rudolphi, Synopsis Entozooriim, p, 251. 



