286 



THE CANADIAN ENTOMOLOGIST. 



took specimens of it at Massett it was known only, Dr. Fletcher says, by 



the type specimen at Washington. Tlie insects are found crawling over 



barnacle-covered stones and boulders near low-water 



mark. Occasionally they occur congregated in a 



mass of several hundreds under a single stone, but for 



what purpose I have been unable to discover. It is 



most abundant in autumn. 



From some experiments I made with several 

 specimens in a dish of salt water in which was a half- 

 submerged stone, I observed that they cannot swim 

 under water, but merely crawl on the stones, their 

 pubescence enabling them to surround themselves 

 with minute bubbles of air. They could not be 

 induced to enter the water from the top of the stone. 



Fig. 



If forced to leave 



the stone they would swim on the surface, but seemed incapable of 

 diving. If touched while on the side of the stone under water, however, 

 they feigned death, and had the power of sinking readily to the bottom. 

 Some that were left all night swimming on the surface of the water were 

 found dead in the morning, while others which had been submerged all 

 night were still active. 



A question has been raised as to whether L. cordicollis^ Lee. (exactly 

 similar to the present species in form, but with the head and thorax 

 brown), is anything more than a colour variety. I have watched both 

 with this point in view, and speaking merely as a field observer, my belief 

 is that they are separate species. Z. cordicollis is the rarer of the two, 

 but when it occurs it is in little colonies. I know, for instance, one large 

 boulder where almost at any time I could take fifty specimens of 

 cordicollis, but where I have never yet seen brevipemiis. I have, more- 

 over, never seen one of each in coitu, though pairs of one or the other 

 are commonly met with. I may add that my view seems to receive slight 

 confirmation from the fact that three other species of submarine beetles 

 occur at Massett with black abdomen and limbs, but with brown head 

 and thorax. On the other hand, however, I have noticed that the brown 

 of cordicollis darkens considerably with keeping. 



TiiJiyrhinus singiilaris., Mann. (Fig. 36.) 



This curious insect seems to be rare in collections, for neither Mons. 

 Fauvel nor the late Dr. Hamilton possessed a specimen till they received 



