Crustacea. 5531 



(H. hortensis), — and will give hira odds of ten to one ! — Alfred Merle Norman ; 

 Kibworth, February 3, 1857. 



Remarks on Henslow's Sivimming Crab (Polybius Henslowii). — This very singular 

 crab has hitherto been considered very rare in the British seas, and its habits, if not 

 altogether unknown, have at most been but little observed. Bell says it is very local 

 in its distribution, and probably nowhere existing in great numbers. It was first 

 discovered by Professor Henslow on the north coast of Devon in 1817, where it was 

 captured in the nets employed in the herring fishery in the early autumn : from that 

 time to the present a few have been taken both on the Devon and Cornish shores every 

 year; on the Cornish coasts they are more numerous on the western than on the 

 eastern shores : they are, however, comparatively much less common in the northern 

 waters (extending from Hartland Point to St. Ives) than on the South, reaching from 

 Plymouth Sound to the Land's End. But they are sometimes common, yet most 

 frequently a few only are captured during a whole season of the pilchard fishery, which 

 extends from June to September ; but, from my notes relating to the captures of this 

 species, I am inclined to think that their apparent rarity is, in a great measure, 

 accidental, depending more on the localities in which the pilchard is taken than on 

 the absence of the crab : I find, for instance, that when the boats fish near the shores 

 or in the sheltered bays, my captures are rare, and during some seasons, when the 

 pilchards are close to the shores, I have been unable to procure a single specimen, 

 and in proportion as they go into deep water the captures are more common. But 

 even when fishing in deep water the seasons are not equally productive, depending 

 probably on the early or late character of the season, or the nature of the tides, and some 

 years seem to be more prolific than others ; but still they are always most abundantly 

 found in deep water, and at considerable distances from the shores. In the years 

 1855 and 1856 the late summer fishery was carried on many miles from the shore in 

 a south-western direction, in the waters of the Lionessa, between the Scilly Islands 

 and the Land's End: from these localities I obtained great numbers every night; in 

 fact, they became at last so abundant that they almost ceased to be interesting. In 

 order, however, to ascertain the probable number taken, one young fisherman, who 

 feels sufficiently interested in Natural History to bring me everything he considers 

 rare, promised to secure for me the whole captured in his boat; this he did, and for 

 about eighteen days I received from one hundred to one hundred and fifty every 

 morning, and on two occasions the number amounted to more than four hundred. If 

 this can be considered as the average capture of all the boats, the sea must have been 

 swarming with them, for the boats of Mount's Bay engaged in deep-sea fishing are 

 more than two hundred, and to these must be added the fleet from St. Ives, for to the 

 west of the Land's End it is a common fishing-ground. I enquired of the crews of a 

 great many boats whether they had taken any, and they all united in stating that they 

 were so abundant as to injure the pilchard fishery. It is altogether a deep-water 

 species, is very rarely indeed, if ever, found near the shore, and I have never seen it 

 washed up after a storm, and only occasionally have I found it among the trawl refuse. 

 Most of the specimens that I have examined have been captured, either by the hand 

 as they swim at the surface or in the pilchard-nets at all depths from the surface of the 



