378 WHITMAN. [Vol. IV. 



s'accoupler chaque annee pour etre fecondees, mais que, semblables en 

 cela a plusieurs inscctes, elles peuvent ne se reproduire que huit ou ueuf 

 mois apres avoir ete fecondees. Ce fait de la reprodiictioti ayant lieu 

 dans U7ie annee autre que celle de raccouplement a d\iilleurs son ana- 

 logue chez une hirudinee non fnedicinale ; car les glossiphonies [Clepsine] 

 que, aux premieres chaleurs du printemps et peu de fours apres leur 

 sortie de leur retraite hivernale, portent souvent deja des mufs sous 

 I'abdofnen, ont certainement ete fecondees dans V annee precedente.^'' 



9. Aidostoma. 

 EBRARD, I.e. p. 67. 



" Deux aulastomes que j'ai trouvdes accoupl^es ^taient rapproch^es 

 tete a tete. Une seule f^condait I'autre ; car je n'apergus qu'une seule 

 verge lorsque je les s^parai. L'une d'elles posa son premier cocon, 

 oeuf polysperme, quinze jours avant I'autre ann^lide." 



10. Macrobdella. 



Copulation has not, so far as I know, been observed in our 

 common Macrobdella. That copulation occurs there can be 

 little doubt. These leeches are remarkable for having so-called 

 " copulatory glands," opening on the ventral side, a few rings 

 behind the $ pore. It was Leidy who suggested that these 

 glands are " provided for the adherence of individuals in sexual 

 intercourse," and their position supports this view. This pecu- 

 liarity makes it all the more desirable to witness the process of 

 copulation. From what we know of other leeches, it is proba- 

 ble that individuals captured in early spring, and kept some 

 days in isolation, would, on being brought together, very soon 

 copulate. 



Observations on Clepsine plana {n. sp.). 



The specimens on which my observations were first made 

 were two large species obtained from Charles River, at Water- 

 town, near Cambridge, in September, 1884. I am unable to 

 identify them with any species hitherto described. Five of the 

 nine individuals captured were dark brown, variously marked 

 with yellow above, and with twelve or thirteen longitudinal lines 

 below ; the remaining four were yellowish brown both above 

 and below. 



