SCOLEX OF A OESTODE. 



75 



This is not a novel conclusion ; but it is not accepted by the, 

 majority of recent writers. Perrier*, the original describer of 

 the genus, found differences in examples from different species of 

 Monitor and recognised two species, viz. Duthiersia expansa from 

 Eastern species of Monitor, and D. elegans from African. Perrier 

 was perfectly right, and the majority of his successors are quite 

 wrong. The confusion of two distinct species is connected with 

 various assertions with regard to the form of the bothria in 

 this genus. It will be necessary to clear up this confusion. In 

 D. expansa the form of the scolex is more spear-shaped than in 

 the other species, as is plainly shown in Perrier's figures. The 

 bothrium on each side is closed posteriorly and opens again by a 

 minute pore closely adpressed to the commencing strobila, thus 

 producing a tube-shaped bothrium open widely in front and by 

 but a narrow orifice posteriorly; this funnel-like arrangement 

 has been justly compared by many to the tube-like bothria of 

 Bothridium (Solenophorus). According to Perrier the same orifice 

 exists posteriorly in D. elegans, but at some distance laterally 

 from the fusion of the bothria with the strobila. Monticelli and 

 Crety f , who examined only examples of Duthiersia from an Indian 

 Monitor, confirmed the existence of the posterior pore in that 

 worm ; and, inferring its existence also in examples from Monitor 

 niloticus from Perrier's statements, united both these worms into 

 one species under the name of Duthiersia Jtmbriata ; this name 

 was given by Diesingj to what he regarded as a species of 

 Solenophorus, though tabulated as "species inquirenda." Diesing 

 made his observations upon Perrier's " species D. elegans. Just 

 previously to the memoir of Monticelli and Crety, Liihe§ took 

 the opposite view and denied the posterior orifice of the bothrium, 

 but agreed with the first mentioned authors in regarding the 

 Cestodes from all species of Monitor as belonging to one species 

 only, namely (of course) D. jimbriata. This view is accepted 

 by Braun || in Bronn's ' Thierreich,' who, in defining the genus 

 Duthiersia, described the hinder region of the bothrium as " nicht 

 perforirt," the italics being his own. It is true that in earlier 

 numbers of the same volume Braun accepted Perrier's statements 

 and even used his figures, but later altered his opinion by reason 

 of Liihe's observations. Still later Shipley ^[ re-asserted the 

 existence of a, posterior opening of the bothria in specimens from 

 Monitor salvator and M. bengalensis, as did Southwell** "In 

 Varanus spp." The latter regards as synonyms both of Perrier's 

 species. Klaptoczft, however, in 1906 again definitely denied the 

 existence of the posterior orifice in the bothria of Duthiersia from 



* Arch, de Zool. Exper. ii. 1873, p. 349. 



t Mem. R. Acc. Sci. Torino, (2) xli. 1891, p. 381. 



X Sitzungsb. Wien. Ak. xiii. 1854, p. 589. 



§ Verh. Deutsch. Zool. Ges. 1899. p. 48. 



|| Klassen u. Ordn. des Thierreiclis, Vermes, Bd. iv. Abth. 1b. p. 1689. 

 1[ Spolia Zeyl. i. 1903, p. 47. 

 ** Bee. Indian Mus. ix. pt. v. 1913, p. 281. 

 ft Sitzungsb. Wien. Ak. cxv. 1906, p. 133. 



