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ARACHNOIDEA. 



CASE some peculiarities of structure in those that have deviated into 

 an aquatic mode of Hfe, and still more when the aquatic mode of 

 life is marine. No other insects have ever been found inhabiting 

 the sea ; certain beetles indeed live under high-water mark, but 

 they are no more sea-beetles than divers are sea-men. Both are 

 terrestrial, and their existence under the sea is exceptional, and 

 provided for in both by special contrivances for breathing. Some 

 mites that have of late years been described as found in the sea, 

 are the nearest approach that we have to insects living in the sea. 

 The first notice we have of any with this peculiarity, either 

 real or supposed, is one which, in 1842, M. Dujardin is said 

 to have found under the sea. It seems to have belonged to this 

 group. Next, three species were described and figured some 

 years ago by M. Laboulbene (Ann. Soc. Ent. Fr. 1851), which 

 had been found (like the above) living between tide marks. 

 He named them Gamasus salinus, G. maritimus, and G. halo- 



philus. The accompanying wood- 

 cut represents his G. maritimus. 

 They all live in the chinks of 

 rocks that are submerged at high 

 water. M. Labculbene says that 

 the two first like to congregate 

 together in great numbers, which 

 may perhaps be partly owing to 

 a whole colony of eggs having 

 been deposited at the same place. 

 These two have a series of tooth- 

 comb-like appendages on the 

 third and fourth articles of the 

 palpi, which are suggestive of the 

 raptorial palpi of the Trombi- 

 diidae ; but the curious prolonga- 

 tions or excrescences which occur 

 in other Gamasi(as in G.tetragonoides) forbid our attaching so much 



Sejus maritimus. Copied from Laboulbene's figure. 

 Very minute. 



