MACALISTEE — ON A.SOABIS DACTYLUR1S. 297 



one individual I saw the wings extending down the anterior part of the 

 body for a considerable distance, and gradually diminishing, until they 

 were lost about half a line behind the head. In one case, also, the 

 naked subglobose head was united to the trunk by a narrow neck, 

 which was bordered by a slight ala. These variations show, I think, 

 how little these appendages per se are to be valued as marks for the 

 distinction of species. I could not associate their presence with any 

 conditions of age or sex ; for, though I only saw them in females, they 

 were by no means frequent in that sex, and seemed completely irre- 

 spective of youth or maturity. 



From the head the oesophagus passes backwards, and is variable in 

 position and length. It is usually curved, with its concavity directed for- 

 wards, and it forms about one third of the entire diameter of the animal's 

 body ; it is not, however, uniform in calibre ; for in some individuals 

 it exhibits slight constrictions, while in others it is dilated into shal- 

 low pouches; its cavity seemed to be like that of other Ascarides, rather 

 triquetrous than cylindrical, and its walls were marked with longitu- 

 dinal striaB ; but whether these were due to muscularity or no I could 

 not positively pronounce, though from the thickness of the coats it is 

 most probable that it is a muscular tube. As remarked by Rudolphi, 

 it is much longer and straighter in males than in females, and varies 

 from one third to one tenth the length of the entire body, being shortest 

 in those females which were crowded with eggs, and longest in the 

 adult males. Its lower end, after a slight constriction, becomes sud- 

 denly dilated into a globose stomach, called by Eudolphi the proveulri- 

 culus, which is very thick in its coats, and filled with a greenish coloured 

 mass ; its cardiac orifice (Fig. 2, d) is rather narrow and constricted, while 

 the pyloric aperture is wider, and when compressed seems somewhat val- 

 vular — the granular contents passing more freely from the stomach to 

 the intestine than in the contrary direction. In some individuals this 

 cavity was perfectly globular ; in others it was slightly conical, and flat- 

 tened. Its usual shape is that of an oblate spheroid, to the poles of 

 which the oesophagus and intestine are attached. A similar globose 

 cavity in Ascaris infecta is described, under the name of gizzard, by 

 Dr. Leidy.* From the inside of the body wall three or four apparently 

 solid curved processes pass to the wall of the stomach, and serve to sus- 

 pend it in the animal's body cavity. The intestine commences by a clavate 

 dilatation, which gradualty narrows, and passes in almost a straight 

 course back to the anus, which is a slit-like orifice, situated a little in 

 front of the tail. Shortly before it reaches this point the gut exhibits 

 a slight enlargement, below which the narrower, sub-cylindrical or 

 pyriform rectum turns off at an obtuse angle, and terminates the canal. 

 Around the constriction, which marks the origin of the rectum, are ar- 

 ranged four small pyriform sacs (Fig. 1 i; and 2, g) — one in front, one on 

 either side, and one posteriorly — granular in appearance, and having 



Smithsonian Contributions," Part 5, p. 43. 

 2s 



