104 Dr. W. C. M'Intosh on the Early Stages in 



Among Polychsetous Chgetopoda the Syllida3 present very- 

 remarkable differences between the gemmiparous and sexually- 

 reproducing conditions, to which the cases here described 

 make a small approach. 



Chatogaster Zimncei. Nais serpentina, 



a. Normal uncinate setae ; h, genital setoe. 



XI. — On the Early Stages in the Develojpment of Phyllodoce 

 maculata, Johnston. By W. C. M'Intosh, M.D., F.R.S.E., 

 F.L.S. 



[Plate VI,] 



Peofessor Saes seems to have been amongst the first to 

 notice the young oi Phyllodoce^ ^ although he was unaware of 

 the group of Annelids to which his young forms belonged. 

 At the end of his paper on the development of Polynoe cir- 

 rata, Linn. [Harmothoe imhricata), he mentions that he had 

 also found, off the Norwegian coast, in February and March, 

 globules composed of irregularly rolled mucous ribands, which 

 adhered to Zostera marina and Fucus vesiculosus at the depth 

 of some feet. These mucous masses with their grass-green 

 ova in all probability refer to the species hereafter to be de- 

 scribed. He observed that the young, on their exit from the 

 egg, had a centi-al circlet of cilia and two kidney-shaped eyes 

 of a bright-red colour. He does not mention a mouth, but 

 states that the anus is at the posterior end of the body, and 

 more visible than in the young of Polynoe. His figure is 

 somewhat small and indistinct, but it would appear to repre- 



* Wiegmann's Archiv, 1845, and Ann. Nat. Hist, 1845, vol. xvi. p. 187. 



