6PECIMS OF (ESTRU& 357 



numerous minute tubercles of the same character with 

 the o'iu'is, excepting that they conform to no regular 

 series; the anterior moiety of the body is entirely 

 glabrous, cylindrical, or rather elongate conic, of a 

 much smaller diameter than the posterior portion, and 

 truncate at the tip ; the lips at the posterior termina- 

 tion of the body are short, and the intervening fissure 

 of but little width. 



Total length eleven-twentieths; greatest width 

 more than three-twentieths of an inch. 



Cabinet of the Academy. 



Observations. From this description we may- 

 gather the facts, that the larva in question corres- 

 ponds with that of (E. bovis in being destitute of 

 hooks or holders at the mouth, but it widely differs 

 in general form, as the larva of bovis is oblong-oval, 

 hardly more narrowed at one end than at the other. 

 The appearance of the series of minute hooks which 

 subserve the functions of feet, in the latter species also 

 are very different from that of the corresponding arma- 

 ture of this larva, the superior line of each double 

 series being narrow and seemingly composed of but 

 a single row of hooks, whilst the inferior line is much 

 more dilated and the hooks far more numerous than 

 in the superior line ; indeed, the series of hooks of the 

 South American larva are more like those of the lar- 

 vse of (E. equi and haemovrhoidalis, than those of the 

 imperfect bovis or ovis. But independently of those 

 considerations, the single character of the much at- 

 tenuated form of the anterior part of the body of this 

 larva, at ouce and eminently distinguishes it from any 



