420 DR J. H. ASHWORTH 



The late Baron de Saint-Joseph revised and extended the description given by 

 Grube, and added observations on some of the internal organs, e.g. the alimentary 

 canal, nephridia, and reproductive organs. Quite recently M. and Mme. Dehorne 

 have given an account of the morphology of this species, dealing especially with the 

 nervous system, eyes, and nephridia, with a discussion of the nature of the funnels of 

 the latter. The other authors cited have either simply recorded the capture of 

 specimens or have briefly referred to their external features. (For an account of 

 the external features see pp. 410-414.) 



Bionomics. — S. minutus lives in shallow water, and has been obtained either by 

 shore-collecting between tide-marks or by dredging. The greatest depth from which 

 it is recorded is 33-35 fathoms (at Cigale ; Grube, 1864). 



This worm has been frequently found between the lamellae of old oyster-shells, 

 and Saint-Joseph suggested that the strong chsetae of the first segment served to 

 excavate a shelter for the worm between the lamellae. On emerging from its retreat 

 S. minutus swims in the water by means of rapid wriggling movements, but soon falls 

 to the bottom and lies on its dorsal surface with the anterior and posterior ends 

 raised and the intervening portion curved. The worm probably feeds on mud and 

 fine debris. 



Colour. — S. minutus is usually reddish brown in colour, but may be a uniform dull 

 brick-red (M'Intosh). A female specimen full of eggs was greyish white (Dehorne). 



Size. — This species has not been found to exceed 20 mm., and most specimens 

 are from 7 mm. to 15 mm. in length. The largest specimens seen by the writer are 

 18 '5 mm. long ; the smallest is one 2'2 mm. long, taken on the surface of the sea off 

 Sark, and kindly lent to me by Professor M'Intosh. 



Distribution. — I have examined specimens from most of the localities from 

 which S. minutus has already been recorded — Lussin Island (Adriatic), Plymouth, 

 Guernsey, Herm, Dinard, and Saint- Vaast. 



Two additional localities may be given here. There are, in the Konigliches 

 Zoologisches Museum, Berlin, several specimens collected by Grube on the shores of 

 Lesina, an island about one hundred and thirty miles south of Lussin. Through the 

 kindness of Dr R. F. Scharff and Mr R. Southern, I have examined a collection of 

 Scalibregmidse from the west coast of Ireland, in which there are specimens of 

 S. minutus from Blacksod Bay and Clew Bay, Co. Mayo. These are the first recorded 

 Irish specimens, and they extend the area of distribution of the species north and 

 west of its previously known range. 



The range of distribution may be stated thus : — S. minutus occurs on the west 

 coast of Ireland, in the English Channel,* along the south coast of France, and on the 

 eastern coast of the Adriatic. 



Type-specimens in Konigliches Zoologisches Museum, Berlin. 



* It will be observed that there is no record of the species from any point in the North Sea. 



