174 



s. GOTO. 



sien. If all the sets of muscular fibres of the body contract at the 

 same time, tlie investing membrane must be subjected to pressure from 

 within, great enough to evaginate the genital atrium and protrude the 

 penis. 



6. Eemarks on the Tcrminolocjij of the Genital Organs — In conse- 

 quence of the complicated relation of the genital organs of the 

 Trematodes the same word has, on the one hand, been often used in 

 different senses l)y different writers, and on the other hand, cor- 

 responding organs have been designated by different names. It may 

 therefore not be quite out of place here to compare, without aim- 

 in "• at exhaustiveness, the terms which have been used '\' confin- 

 ing our attention mainly to the ectoparasitic Trematodes. In his 

 " Sa<>"o'io " Monticelli used the term " ovidotto interno " forthat 



CO 



portion of the female efferent duct which lies between the ovary and 

 the ootyp ; the latter he called "utero"; Avhile the remaining por- 

 tion, i. e., the portion lying between the ootyp and the external 

 opening, he called " ovidotto esterno." In his recently published 

 " Primo contributo," however, he uses these terms in other senses. 

 Leaving the " ovidotto interno " ^\it\\ the same sense, he now ap- 

 plies the term " utero " to that portion which lies beyond the shell- 

 glands and which "conserva lo stesso calibro," and "ovidotto 

 esterno" for " sua porzione terminale, dove si allarga ad imbuto molto 

 allungata." The term " ootypo " he uses in the sense given it in the 

 present paper. 



Wright and Macallum in their pnper on .S';)////rf//i»m apply 

 the term " uterus " to the ootyp, and use the latter term for that 



1). The descriptions of Vogt ia his paper, " Ueber die Fortpflinznngsorgane einiger 

 ectopavasitischer mariner Trematoden " (Zeitsch. f. wiss. Zool., Bd. 30, Suppl, 1878, p. 306-340) 

 are unfortunately so imcomplete and obscure that I could not make much use of them. His 

 terminology will not therefore be considered here, lest I should misinterpret his observations. 



