266 



Emanationen zum Ausgangspuncte — wenn nicht etwa dem äußer- 

 sten Endabschnitte der Eileiter, der mit dem Ductus ejaculatorius 

 gleichwerthig zu sein scheint. Dieses negative Verhalten steht wohl 

 in Beziehung zur ausgiebigen';In volution, welche das Nymphalstadium 

 über die paarigen Eileiter überhaupt verhängt. 



10) Zwischen männlichen und weiblichen Nebenorganen der Ge- 

 schlechtsausführungsgänge besteht gar keine Homologie, indem jene 

 des Männchens — accessorische Drüsen , Samenblasen und Ductus 

 ejaculatorius — mesodermalen Ursprungs sind, jene des Weibchens 

 dagegen — Begattungstasche, Samenkapsel, Kittdrüsen — rein ecto- 

 dermal entstehen. Was die Muskelhäute der weiblichen Anhangs- 

 organe und Ausführungsgänge betrifft, so ist hervorzuheben, daß jene 

 des Uterus von den Genitalsträngen abstammen, während die Deri- 

 vate des vorderen und des hinteren Imaginalscheibenpaares aus be- 

 sonderen Zuzügen des intervisceralen Muskelnetzes ihren Bedarf be- 

 ziehen. 



Padua, den 25. März 1896. 



4. Preliminary Note on the anatomy of Actinotrocha and its bearing upon 

 the suggested Chordate affinities of Phoronis. 



By Arthur T. Mast er m an, B.A. Lecturer and Assistant Prof, of Zoology in the 

 University of St. Andrews. 



eingeg. 9. April 1896. 



At a meeting of the Royal Society of Edinburgh last month 

 (March) a note upon the structure and affinities of Phoronis was read 

 and therein were put forward reasons for holding that Phoronis is 

 closely allied to the three genera [Balano glossus ^ C ephalo discus ^ and 

 Rhahclopleiira] which are, by most English naturalists, placed together 

 in the group «Hemichordata« It was pointed out that, due allow- 

 ance being made for the sedentary degenerate habit of Phoronis, 

 its anatomical resemblances partly to Balanogloasus ^ and partly to 

 Cephalodiscus , are so striking that even the a\)sence of a notochord 

 and of gill- slits should perhaps hardly militate against its claims to 

 a place amongst the Chordata. At the same time, according to the 

 principles of ontogenetic repetition of phyletic vestigial organs, it was 

 suggested that some vestige of a notochord should be presented in the 

 Actinotrocha stage before the loss of the prc-oral lobe and the well- 

 known metamorphosis. 



A preliminary examination of spirit specimens of Actinotrocha 

 has yielded such remarkable results that I thought it best to oriefly 

 state the leading points in this note. Not only do I find in Actino- 

 trocha an organ which appears to be the homologue of the notochord 



