MARINE MITES. 207 



CASE independent of that, the Oribatidse have a very remarkable 

 breathing apparatus, which is either absent in the Halacaridse, or, if 

 present, has not yet been ascertained to exist. The latter seem 

 to us to have more affinity with the Bdellidae than with the Trom- 

 bidiidae ; for most of them (not all) have a projecting snout, and 

 some of them antennae like palpi, and the Bdellidae have their 

 legs starting nearer from the margin of the body than the Trom- 

 bidiid^, although not from the edge like the marine mites. But, 

 in fact, they have points of resemblance with several families ; and, 

 what is curious, characters which, in other families, are of primary 

 importance (as, for instance, the transverse division between the 

 thorax and abdomen), seem here to have lost their value, some 

 having it and some not. Looking at the group altogether, how- 

 ever, we have no hesitation in coming to the conclusion that it 

 belongs neither to the Bdellidas, the Trombidiidse, nor Oribatidae, 

 and still less to any other less similar group. We, therefore, 

 propose to establish a new and distinct family for its reception ; 

 and not to hamper it with more characters than we can help, or 

 with any that are difficult to find, we shall define it as mites living 

 habitually under the sea, having either a stiff or a more or less 

 rigid, cuirassed skin, and with their legs springing from the outer 

 margin of the body. 



These little creatures have been chiefly obtained by dredging, 

 or from seaweeds in rocky pools of sea water, weeds between tide 

 marks, &c. They have also been observed creeping on the stems 

 of seaweeds or zoophytes, or on the sides of marine aquaria, a 

 mode of obtaining them, which has the great advantage of allowing 

 their form, ways, and habits to be studied while they are alive. 

 Where they do occur, it appears to be in considerable numbers. 

 Mr. Brady remarks, that in some dredgings made off the coast of 

 Durham and Yorkshire, the number of individuals was very con- 

 siderable, almost leading one to the belief, that they must, in favour- 

 able spots, colonize the mud almost as thickly as their better 

 known relatives do a decaying cheese. 



