340 PEOPESSOR EAY LANKESTEE AND A. G. BOUENE. 



On the Existence of Spengel's Olfactory Organ 

 and of Paired Genital Ducts in the Pearly- 

 Nautilus. 



By 



E. Ray liankesfer, IVI.A*, F.R.S.i 



Jodrell Professor of Zoology, 



and 

 A* G. Bourne, B.Sc* 



A MALE and a female specimen of Nautilus pompilius 

 were purchased a few years since by one of us for the Zoolo- 

 gical Museum of University College, London. Leisure and 

 opportunity for the study of these specimens have recently 

 been afforded, and we propose to briefly report here on two 

 interesting additions to knowledge which our observations have 

 yielded. 



The specimens were in an excellent state of preservation for 

 the purpose of dissection, though not fit for histological study. 

 The male was not purchased as such, and its sex was not re- 

 cognised until it was withdrawn from its shell and the circum- 

 oral tentacular apparatus examined. 



With the exception of the specimens reported on by Van der 

 Hoeven no adult males of Nautilus have been carefully ex- 

 amined, that referred to by Keferstein (in Bronn's ' Classen 

 und Ordnungen des Thicrroichs,' Weichthicro) being an imma- 

 ture specimen. A description and figure of tlie circum-oral 

 tentacular apparatus of the male Nautilus and a comparison of 

 this with the corresponding region in the female will form the 

 subject of a memoir by Mr. liourne in another publication. 

 Here we shall confine ourselves to two points. 



