PIPETTA WEBERI, n. g, et n. S p., 

 WITH NOTES ABOUT TIE PROBOSCIS OF THE PYCNOGONIDA, 



BY 



J. C. C. LOMAN 



(with 7 Figures.) 



The proboscis of the Pycnogonida is a limb which, from the 

 outset, has hampered the study of the affinity of this group by 

 its peculiar combination of three autimeres. The theory of the 

 ancient writers, who took the proboscis to be a coalesciou of parts 

 of the mouth, became untenable since it was not found to be sup- 

 ported by a single fact in the history of' its development and the 

 anatomy. It only needs to be mentioned in the History of Zoology, 

 to prove that, on new views being introduced in science, everybody 

 seems bent npon generalising them. This was the case after Savigny's 

 famous treatise on the homology of the organs of the mouth in 

 articulates '). The proboscis was then at once classified under the 

 fused mouth-parts without further investigations, and this erroueous 

 opinion remained the prevailing one for a considerable time. 



The first to exhaustively discuss the matter in the light of his 

 own researches, was Uohrn. He comes to the conclusion that 

 the organ is simply a highly developed stomodaeum and has 

 nothing to do with the growing together of mandibles and lips. 

 The exact quotation is 2 ): »Der Schnabel ist eine Bilduug sui 

 generis, die keine Analogie bei andera Arthropoden findet. Er ist 

 eine nachtragliche Abgliederung des vordersten Ruinpf-Seginentes 

 und enthalt das grösste Stück der Vorderdarin-Einstülpung (Sto- 



1) Savignt, Theorie des organes de la bouche des Crustacés et des Insectes, 181 G 



2) Dourn, Pantopoden des Golfes von Neapel, monogr. 1881, p. 247. 



