964 SUMMARY OF CURRENT RESEARCHES RELATING TO 



species agrees generally in the disposition of its venous system with 

 O. muricicola ; well-marked eyes are present. Like the just-mentioned 

 species, G. Brauni has a kind of boring apparatus by means of which it 

 is able to penetrate the body-wall of its host. The successive hermaphro- 

 ditism of the genital products is not quite so well marked as in G. muricicola 

 or G. thetydicola, for in moderately sized examples all the parts of the male 

 apparatus are developed, while the female germ-glands were already ripe, 

 and it was only in the largest individuals, where the ovaries were greatly 

 developed, that the tubes were found to have completely disappeared. The 

 female apparatus consists of germ-glands, vitellaria, atrium genitale with 

 its appendix, receptaculum seminis, and shell-glands; the uterus com- 

 municates with the exterior by a very narrow genital canal. As in the 

 two species already mentioned, the germ aria have no membrane. In quite 

 young individuals the ovary consists of a mass of finely granular proto- 

 plasm in which numerous nuclei are scattered; in the organs of older 

 animals the protoplasm breaks up into the characteristic germinal discs. 



G. Brauni appears to have an excretory system which differs a good deal 

 from that of G. muricicola. Where a specimen is examined from the dorsal 

 side, two large pyriform vesicles may be seen in the anterior fourth of the 

 body ; these open to the exterior by an extremely short fine canal between 

 the epithelial cells. From each vesicle a ramifying canal extends backwards 

 and forwards, but these could not be traced far, and they doubtless become 

 very fine. The vesicles are invested by an extremely delicate membrane. 



Dendrocoelum punctatum.* — Dr. W. Weltner gives a description of 

 the large Planarian Dendrocoelum punctatum Pallas, which he found in the 

 Tegelsee and also in the Spree near Berlin. He notes the external 

 characters, the formation of cocoons, the number and appearance of the 

 larvEe, but as his results are for the most part corroborations of the investi= 

 gations of de Man and Hallez, the communication is almost exclusively of 

 faunistic interest. 



5. Incertae Sedis. 



Dicyemid9e.| — Prof. M. Braun gives an account of what is known as to 

 the curious parasites called Dicyema, first observed by Krohn in the 

 " venous appendages " of the Cephalopoda, which will be useful for those 

 who are unacquainted with the investigations that have been made on 

 them. He concludes with a list of known species taken from Prof. Carus's 

 ' Prodromus Faun^ Mediterranese,' 



Anatomy and Systematic Position of Echinoderes.J — Prof. W. Eein- 

 hard gives a detailed account of the anatomy of this enigmatic worm, and 

 discusses the various suggestions that have been made as to its systematic 

 position. He is himself inclined to associate it most closely with Annelids. 

 With regard to its segmentation he is unable to accept the view of Hatschek 

 that it is merely external and due to their mode of locomotion. The 

 forward movements of Echinoderes are performed by the aid,of the proboscis, 

 and all other movements are very feeble. In his view, segmentation has 

 not been independently acquired, but has been inherited ; it is not only 

 the outer covering that is segmented, but the whole body-wall corresponds, 

 while in each segment there is a thickening separated by a constriction 

 from its successor. 



The most important peculiarity, in Prof, Eeinhard's opinion, is the 



* SB. K. Prcuss. Akad. Wiss., 1887, pp. 795-804 (1 pi.), 



t Centralbl. f. Bakteriol. u. Parasitenk., ii. (1887) pp. 386-90, 



: Zeitschr. f. M'iss. Zool., xlv. (1887) pp. 401-67 (3 pis.). 



