Manners, &)C. of some of the British Brachelytra. 123 



Tachyporl, Sec.,) and the changeable gloss of the pubescence, 

 render this genus distinguishable at the first glance : none of the 

 species appear to be numerous in individuals, and different speci- 

 mens vary considerably in size and brilliancy : one of my specimens 

 of R. semiohscurus is nearly 5 1 lines in length. 



R. hoops has been several times taken near Oxford by my friend 



A. Matthews, Esq. 



R. rufipennis I took in the Scilly Islands, the only species of 

 the genus which I found there during my short stay : the golden 

 gloss of the pubescence gave the insect a most beautiful appear- 

 ance when alive. 



R. semiceneus I have taken in Gloucestershire, and I think in 

 Cornwall also, but I do not find it in my local catalogue. 



The B'lsnii, though found, as remarked by Mr. Stephens, as 

 well under dung as under fuci, seem never to occur at any 

 distance from the coast : I never took a single specimen inland. 



B. cephalotes I found in considerable plenty at Southend, in July 

 last. 



The different species of Cafius occur in great plenty under sea- 

 weedj in all parts of the coast, but are so exclusively maritime in 

 their locality that I never saw a single one beyond the limits of 

 the sea-beach. They are highly predacious, and are well fitted 

 for rapine by their broad heads and long jaws armed with powerful 

 dentations : on turning up a heap of sea-weed, they may fre- 

 quently be seen, particularly when the sun shines, to spring into 

 the air after the flies thus disturbed, aiding their dart by a mo- 

 mentary expansion of the wings. Their voracity does not even 

 spare their ow n species : the larger specimens prey on the smaller 

 without mercy, and I have seen two leave a common prey un- 

 touched while they fought for its exclusive possession. They 

 burrow with great agility under the loose sand when alarmed, 

 their flattened body, and expanded and pilose anterior tarsi, being 

 admirably adapted for making their way through this loose mate- 

 rial : though they frequently content themselves with merely 

 thrusting their heads under a pebble and remaining motionless, 

 apparently thinking, as popular belief attributes to the ostrich, 

 that they are thus effectually concealed. 



The distinguishing characteristics of the different species in this 

 genus have somewhat perplexed me, from the great variation 

 observable in different specimens: the first species, C. fucicola, 1 

 have never been able satisfactorily to identify among my speci- 

 mens : and I have sometimes doubted whether the two next, 



C. xantholoma and C, lateralis, might not in reality form a single 



