DEFINITION OF BOTHEIOCEPHALUS LATUS. 683 



not with the suckers (oscula suctoria) characteristic of the genus 

 Tcenia, but with suctorial grooves (bothria). This included forms of 

 very varied structure, with two or with four grooves, and with or 

 without hooks on the head. These were afterwards classified, and 

 that almost contemporaneously, by my uncle, Fr. S. Leuckart, in his 

 well-known monograph of the genus Bothriocephalus* and by Eudolphi 

 himself (1819) in his " Entozoorum synopsis." The genus was, indeed, 

 conserved in its whole extent, and indeed enlarged by my uncle to 

 the extent of including the segmented Tetrarhynchi, previously 

 separated by Eudolphi; but within the genus both Eudolphi and 

 Leuckart distinguished, according to the structure and armature of 

 the head, a number of smaller groups, which are still, for the most 

 part, retained, except that they now represent genera or even families. 

 The species which remain after the separation of the Tetrarhynchi are 

 those which, in Eudolphi's system, formed the "Inermes (gymno- 

 bothrii) dibothrii" of the first group, which Diesing afterwards 

 collected under the generic name Dibothrium. Including several 

 doubtful forms, the latter enumerated in this genus thirty-two species, 

 all of which, with the exception of one doubtful case, infest the 

 alimentary canal of mammals, birds, or fishes. The suctorial grooves 

 are said to be sometimes marginal, sometimes placed on the flat 

 surface ; but recent investigations seem to have made it questionable 

 whether any forms with marginal grooves really exist. The descrip- 

 tion, formerly so generally accepted, has, in the case of Bothriocephalus 

 lotus at least, proved to be erroneous. 



Bothriocephalus latus, Bremser. 

 Taenia lata, Linnd, incl. T. vnlgaris, Linn6, et T. tenella, Pallas. 



Bremser, " Lebende Wiirmer im lebenden Menschen," 1819, pp. 88-96. 

 Botticher, " Studien uber den Bau des Bothriocephalus latus," Archivf. pathol. Anak, 

 Bd. xxx., pp. 97-148. 



Short-jointed, broad and flat, of considerable length up to 8 to 9 m., 

 "but usually shorter. The number of segments amounts, in long speci- 

 mens, to at least 3000 to 3500. With the exception of the last few, the 

 joints rarely measure more than 4 to 5 mm. (usually 3 to 3'5 mm.) in 

 length, while their breadth increases gradually to 10 or 12 mm. and 

 more (occasionally to as much as 20 mm). Posteriorly, the proportions 

 are somewhat altered, inasmuch as the breadth of the segments decreases 

 and the length increases, until the previous form is replaced by a square, 

 or even slightly elongated rectangular form. The body is usually thin 



1 "Zoologische Bruchstucke," i. : Helmstedt, 1819. 



