621 



As far as any original ubservations are concerned Molin's 

 species T. tetragona then rested for a number of years. 

 In 1880 Megnin (1880, p. 119) mentioned T. echinobothrida as a 

 nonien nudum. In 1881 two parasites of chickens, very similar 

 to if not identical with T. tetragona, were described as new. 

 Megnin described and figured T. echinobothrida as new species 

 with the characters given in the diagnosis above (p. 618.) A 

 careful study of both figures and description shows that the 

 most important characters at present to be considered are the 

 hooks upon the rostellum, said to he about 100 in number, 8 

 H long, the rows of hooks upon the suckers (6-7 rows), those of 

 the middle row being the largest; genital pores irregularly al- 

 ternate; eggs 90 /x in diameter, spherical, arranged in groups 

 of 6-7 in 'roundish ess capsules. 



In March of the same yeari (1881) Plana (1882, pp. 387-391, I 

 plate) presented a paper before the Accademia delle Scienzei di 

 Bologna, in which he described as a new species T. bothriop- 

 litis, a cestode which he found causing serious damage to poul- 

 tiT, producing tubercles in the intestine. The chief zoological 

 characters taken as a basis for the species are as follows: 



Head 0.35mm jn diameter; retractile hemispherical rostellum 

 armed with hooks (number not given, but evidently ca. 200, 

 form shown in drawing); suckers with seven or eight concen- 

 tric rows of hooks (form as per drawing), hooks not all of same 

 size; neck very long, containing ovoid calcareous corpuscles; 

 genital pores unilateral, situated somewhat below (distally) the 

 middle of the lateral margin; cirrus short, pyriform; eggs in 

 egg sacs. 



Plana states that Rivolta and Delprato (in Ornitojatria, 1880, 

 T. I., f. 5a— not accessible to me) picture the head of a cestode 

 which produced similar nodules in the intestine of a chicken. 

 Plana found 2 cysticercoids in Helix (whether in H. carthu- 

 sianella or H. maculosa is not clear to me) which agree quite 

 closely with the head of the parasite found in chickens; no 

 experiments were made to demonstrate that this cysticercoid 

 is the larval form of the worm in question, but their specific 



iThe date of publication of the volume for 1881 is given upon 

 the cover as 1882, but a preliminary notice of this paper ap- 

 peared in the Rendiconto in 1881. This preliminary notice, 

 however, is altogether too incomplete to hold should the ques- 

 tion of priority be raised between Megnin's T. echinobothrida 

 and Piana's T. bothrioplites. Further, as Plana cites Megnin's 

 article in the final paper, Megnin's name must be given prece- 

 dence, should these two forms prove identical. Piana's T. 

 bothrioplites of 1881 is to all intents an<T purposes a nomen 

 nudum, and his species T. bothrloplitis should be dated 1882. 



