190 Dr. M. T. Newbiglu o,i 



Literature quoted. 



Hauser, G. (1880). — Zeitschrift fiir wisaen. Zool. Bd. xxxiv. pp. 3l57- 

 403, Taf. iii. 



Kraepp:lin, K. (1883). — Ueber des Genichsorgane der Gliedertiere. 

 48 pp., 3 Taf. Hamburg. 



Mayer, A. G. (1897). — Bulletin Museum Couap. Zool. at Harvard 

 College, vol. xxx. pp. 178-180, pi. iii. figs. 24-41. 



Packarb, a. S. (1898).— a Text-book of Entomology. Pp. vi, 729 ; 

 654 figs. Macmillan & Co. 



Plateau, F. (1897).— Bull, Acad. Roy. Sci. Belgique, torn, xxxiv. 

 pp. 601-644, 847-880. 



SouLE, Caroline G. (1894). — 'Psyche': the Journal of the Cam- 

 bridge Entomological Club, vol. vii. p. 155. 



Harvard University, 

 Cambridge, Massachusetts. 



XXII. — On Briiish Species o/' Siphoiio-stoiiia. 

 By M. I. Newbigin, D.8c. (Lond.). 



[Plate IV.] 



The two most familiar species of" Siphonostoma (FlaheUvjera) 

 are S. ajffinis, the typical northern form, and S. diphchaxlos ^ 

 the typical Mediterranean form. It is, however, worthy of 

 notice that while Cunningham and Ramage * suggest that 

 the two are identical, St. Joseph f says there can be no possi- 

 bility of confusion between the two. In the vicinity of 

 Millport Marine Station a species of Siphonostoma occurs in 

 great abundance in the nests of Lima hians, and a collection 

 made there during this summer has enabled me to make some 

 observations on the specific characters. For purposes of 

 comparison, Mr. E. J. Allen, of the Plymouth Marine 

 Station, kindly furnished me with twenty-one specimens of 

 the species found in the neighbourhood of Plymouth. The 

 two forms are distinct, the Millport specimens agreeing most 

 closely with S. diplochaitos. Otto, the Plymouth specimens 

 with S. affinis, Sars, as defined by St. Joseph. Before pro- 

 ceeding to describe the specimens, it may be well to give in 

 tabular form St. Joseph's list of the specific differences between 

 the two : — 



* " Polychseta Sedentaria of the Firth of Forth," Trans. Roy. See. 

 Edin. xxxiii. (1888), p. 677. 



t " Ann^lides Polychetes des Cotes de Dinard," Ann. Sci. Nat. (Zool.) 

 xvii. (1894) p. 96. 



