190 Dr. M. I. X.'wbigln on 



Literature quoted. 



HArsKR, (i. (18S0). — iieitscbrift fiir wissen. Zool. BJ. xxxiv. pp. 307- 

 403, Taf. iii. 



Krakpklix. K. (1883). — Ueber des Genicliaorgane der Gliedertiere. 

 48 pp , 3 Taf. Hamburg. 



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

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



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

 6o4 figs. Maciuillan & Co. 



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

 pp. 601-644, 847-880. 



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

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



Harvard University, 

 Cambridge, Massachusetts. 



XXII. — On British Species o/' Sipliotiostoma. 

 By M. I. NewbigIxN, D.Sc. (Load.). 



[Plate IV.] 



The two most familiar species of kiphonostoinn {Fhibelli'/era) 

 are S. offinis, the typical northern form, and S. diplocha'itos, 

 the typical Mediterranean form. It i.s, 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 Siphonostmia occurs iti 

 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. o^riis, 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 : — 



* " Polvchseta Sedentaria of the Firth of Forth," Trans. Rov. Soc. 

 Edin. xxx'iii. (1888),p. 677. 



t " Ann6hdes Polychetea des Cotes de Dinard," Ann. Sci. Xat. (Zool.) 

 ivii. (1894) p. 96. 



