20 A FLOKA WITHIN ANIMALS. II. 



2. Enterobryus spiralis, Leidy. 



Proc. Acad. Nat. Sci., Phila., iv., 249. 



(Plate I. Fig. 4.) 



Thallus brownish, yellowish, or hyaline, cylindrical, forming a single, double, or 

 triple spiral. Pedicle cylindroid, expanded at base, or elongated conical, not con- 

 torted, smooth, or faintly striated longitudinally, brownish or yellowish in color. 

 Principal cell cylindrical, slightly dilated at the extremities or uniform throughout. 

 Penultimate cell cylindrical. Terminal cell clavate, curved, obtuse. 



Whole length, from yV to -gV i"ch. Length of pedicle, -^-^-^'mch.; breadth, g^-g- 

 to ¥2VTr inch. Breadth of principal cell, ^J-^T i^^h. Length of penultimate 

 cell, ^lo to ^^0 inch; breadth, -^-^-^-^ inch. Length of terminal cell, -^\-q to -^-Jo- 

 inch ; breadth, -^-^-^-^ inch. 



Habitation. Attached to the mucous membrane of the small intestine oi Julus 

 puiillus. 



3. Enterobryus attenuatns, Leidy. 



Proc. Acad. Nat. Sci., Phila., iv., 249. 



(Plate I. Figs. 2, 3; PI. III. Figs. 15-17 ; PI. IV. Figs. 26, 27.) 



Thallus faintly brownish, 3'ellowish, or hyaline; forming at first a double flexure 

 or sigmoid curve, and then proceeding in a straight or gentle curvilinear direction 

 to its free extremity. Pedicle short, cylindroid, campanulate, or conical with a 

 spreading base, longitudinally striated, simple, occasionally double, uniformly yel- 

 lowish. Principal cell cylindrical, attenuated at both extremities, or very slightly 

 and gradually narrowing from the commencement, or uniform throughout; trun- 

 cated, or obtusely rounded at the free extremity. Terminal cells rare. 



Whole length i line to 1 line. Length of pedicle g-|^g to -^^-^ inch by -2 sVu to 

 ^^^ inch broad. Diameter of principal cell; at middle, ygVo' inch; at sigmoid 

 curve, 2-3V0" inch ; at the free extremity, ^-to-^- In other instances, y^^- inch at the 

 sigmoid portion, and gradually decreasing to j^Vo' inch at the free end. Where 

 uniformly cj'lindrical, about the jyVo" inch in diameter. 



Habitation. Grows from the mucous membrane of the ventriculus of Passalv,s 

 cornutus. 



§ 4. History, Structure, etc. of Enterobryus. 



I first discovered the genus of entoparasitic plants, Enterobryus, in the small 

 intestine of Jidus marginatus, in the autumn of 1848, but published no account 

 of it until October of the following year. From its structure, I immediately sup- 

 posed it to be a plant; but afterwards, from the constancy of its existence in the 

 small intestine, and firmness of attachment to the mucous membrane of the latter, 

 I began to suspect it might be a part of the structure of the viscus in which it was 



