186 TAPE WORMS OF HA ES A XD I? ABB I TS S TILES. VOL. xix. 



is too indefinite to allow a specific or even generic determination. In 

 1803 he transferred the species to Halt/sis. 



Eudolphi l in 1810, as Eiehni remarks, certainly had more than Goeze's 

 species in mind when he wrote his diagnosis; a portion of his descrip- 

 tion applies very well to C. denticulata, and a portion to C. ctenoides. 

 He includes Zeder's single-pored form in T. pectinata. The fragment of 

 Eudolphi's (1810) specimen of T. pectinata which I examined is so 

 poorly \ (reserved that no statements can be made on it, but. as Stiles 

 and Hassall in 1896 have shown, part of Eudolphi's original material 

 of T. denticulata belongs to this species. 



Bremser 2 in 1824 gives two figures of T. pectinata, in regard to which 

 Eiehm remarks that Figure 5 is an unquestionable I), leuckarti, while 

 Figure G (head) is similar to D. latissimum (=C. denticulata}. 



Diesing's 3 description of 1850 can be made to apply to several dif- 

 ferent forms; he includes all the literature given for T. pectinata. 



Our chief knowledge of C. pectinata we owe to Eiehm in 1881, who 

 studied its anatomy in detail. Eiehm divided the heterogeneous mass 

 of tapeworms, which earlier authors had included under the term 

 T. pectinata^ into five species, which he named T. rhopalocephala and 

 T. rhopaliocephala (single-pored forms), and Dipylidium pectinatum, D. 

 leuckarti, and D. latissimum (double-pored forms). This is the first 

 time, therefore, that T. pectinata was described in detail, so that this 

 species stands to-day upon Riehm's division, he having designated the 

 particular parasite which should bear Goeze's specific name. 



Eiehm 4 diagnoses his form as follows : 



Kopf hakenlos, ausserordentlich kleiu, kaum inni. breit, gegen die lanzettfor- 

 mig sicli verbreiterndo Strobila nicht abgesetzt. Geschleehtsorthungen beidei>eits, 

 fast in der Mitte des Proglottidenrandes. Glieder kurz, trapezforrnig, anch im 

 gestrecktesten Zustande miudestens 4 mal breiter als lang. Liiiige des ansgestreck- 

 ten Wurmes niclit iiber 40 cm. rneist geringer. Breite der reifsteu Proglottiden bis 

 8 mm. Die Strobila ist oft durch Liingsfalten gestreift. Wohntliier: Lepus timid us. 



This diagnosis is hardly detailed enough to meet the requirements of 

 the present day, but in the anatomical description Eiehm gives data 

 which supply what is lacking in the passage just quoted. Many of the 

 points he mentions can hardly be looked upon as specific characters, 

 but should, I believe, be attributed to influences of technique, individ- 

 ual variation, and possibly the specific influences of environment, 

 namely, the host a subject to which the helminthology of the future 

 must certainly give its most serious and careful consideration. The 

 characters which appeal to me most in Eiehm's description may be 

 briefly summarized as follows : 



Male organs: The testicles form a continuous band across the median field in the 

 distal portion of the segment, and in Plate VI, fig. 4, they extend laterally close to the 



J Entozooruui sive Vermium intestinalium Historia naturalis, II, Pt. 2, Arnstelse- 

 dami, pp. 82-84. 



2 Icones Helminthum, pi. xiv, figs. 5-6. 

 3 Systema Helminthum, I, 1850, p. 498. 

 4 Loc. cit., p. 575. 



