11 



914 EEPORT OF COMMISSIONEE OF FISH AND FISHERIES. [36] 



If we now turn to PI. I, Figs. 4 and 1, we find here representations of 

 the copulative organs of two different species. It is most reasonable 

 to suppose that the copulative organs of the species in the same family 

 are formed in the same x)riucipal way, and that no very large variations 

 will occur in nearly related genera. If, therefore, the exterior coating 

 of the atrium in one species ends above the oviduct, it is also reasonable 

 to suppose that it will do the same in other species of the same family. 



According to the drawings of Claparede this is, however, not the case. 

 In the figures last referred to the penis sheath is seen in both, but in- 

 stead of inclosing the penis, or lower end of atrium, it is represented as 

 inclosed in the same. The oviduct is seen as if connected with the ex- 

 terior coating of the atrium, and any organ resembling the oviduct as 

 figured for Tubifex is not to be found. This, however, is in full accord- 

 ance with the description. 



To me it appears that Claparede, in studying the Tubifex, really dis- 

 covered the nature of the oviduct, but misunderstood it in trying to 

 reconcile its aspect with his old ideas and those of previous investi- 

 gators. Why the exterior coating of the atrium should be considered It 

 as an oviduct I cannot readily see. It would be far more natural to ' 

 think that both the spermatozoa and the ova were captured by the same 

 funnel-shaped organ and conveyed through the efferent duct to the | 

 genital porus. Besides, if the exterior coating of the atrium is con- 

 sidered as the oviduct, what then are all the peculiar funnel-shaped 

 organs surrounding the penis and the penis sheath ? 



The coi)ulative organs of Psammoryctes, as described by Vejdovsky,* 

 exhibit some characteristics similar to those of Tubifex^ as they are un- 

 derstood by Claparede. 



In Fig. 9, Taf. VIII, the ovd. represents evidently the exterior 

 sheath of the oviduct, and the lower bell-shaped organ surrounding the 

 penis and connected with the atrium is perhaps the interior sheath of 

 the oviduct. The interior aperture is, however, not delineated, and 

 must, I think, be sought for in the neighborhood of g b. If such an 

 aperture really exists, the whole organ resembles, to a considerable 

 extent, not only the same of Tubifex Bonneti, but also that of the most 

 of the new species described in this paper, especially so Tubifex Campa- 

 nulatus. According to the above figure the ova pass between the 

 exterior oviduct and what I have designated as the interior sheath of 

 the same. I have myself had no observation on this point, and must 

 reserve my opinion until some future time. 



We will now again return to our new species, and more minutely 

 review their copulative organs and compare them with each other and 

 with those of formerly known species. 



In a preliminary reportt on this subject I stated as my opinion that 



— -1 . 



* Zeitschrift f. w. Zoologie, Bd. xlvii. IJeber Psammoryctes. 



t Preliminary report on genera and species of Tubificidse, by iGrustaf Eisen. Bihang 

 till k. Svenska Vet. Akad. Handlingar, Band 5. No. 16. 1879. 



