224 ILLINOIS BIOLOGICAL MONOGRAPHS [224 



of Diesing's list of hosts. Nowhere does Schwarz state definitely the 

 exact host from which his specimens were taken. A study of his de- 

 scription in comparison with other species from snakes shows that his 

 specimens are most closely related to the species from Colubrinae yet 

 they are distinct from any of those species. It seems then quite prob- 

 able that his specimens came from one of the Colubrinae, Coluber sp. 

 and possibly Ophiomorphus miliaris or Ophis merremii. They surely 

 did not come from Eunectes, and it is highly improbable that they came 

 from Bothrops, one of the Viperidae. The emended list of hosts of 

 Taenia racemosa then contains these names, Coluber sp., Ophiomorphus 

 miliaris and Ophis merremii. Further questions regarding Schwarz 's 

 Taenia racemosa arise. Is his species identical with Eudolphi's Taenia 

 racemosa? Could Schwarz have had any of Rudolphi's type material? 

 At the writer's request Professor "Ward wrote to Professor E. von Mar- 

 enzeller at Vienna for information concerning the specimens of Taenia 

 racemosa which he had sent to Barrois and to Schwarz. Professor von 

 Marenzeller replied that all of Eudolphi's types were in the Museum at 

 Berlin. It is therefore impossible that Schwarz or Barrois had Rudol- 

 phi's type specimens for examination and the question of the identity 

 of Schwarz 's Taenia racemosa and Rudolphi's species of that name re- 

 mains open and must so remain until Rudolphi's types are re-examined, 

 if they still exist. Meanwhile the writer assumes that the Taenia race- 

 mosa of Schwarz and Rudolphi are identical. 



Schwarz 's material all came originally from the Museum at Vienna, 

 some directly through von Marenzeller, and some through von Maren- 

 zeller to Barrois, then from Barrois to Schwarz. As hosts he mentioned 

 four species of South American snakes two of which have been ruled 

 out in the above discussion, leaving either or both Ophis merremii and 

 Ophiomorphus miliaris as probable hosts. If the specimens were from 

 Ophis merremii they were probably collected by Natterer in Brazil. 



The following description is based on the work of Schwarz (1908). 

 The observed length of specimens was 160 mm., length of ripe proglottids 

 2 mm. and the breadth of the same 1 mm. The scolex (Fig. 140) is 

 readily distinguished from the strobila. It bears four nearly circular 

 suckers which measure 0.270-0.300 mm. in diameter. The scolex has a 

 diameter of 0.540 mm. 



The sexual organs (Fig. 191) agree in arrangement with the genital 

 organs of other Ophiotaenia. The testes are of exceptional size, 0.072- 

 0.078 mm. in diameter, appearing as large spheres. They are not limited 

 to the side fields but are scattered irregularly through the whole area 

 of the segment. The testicular field is not interrupted at the anterior 

 or posterior margin of the segment. Testes number about 100-120. The 



