22 



tions and the microscope shows that it is made up of a clear 

 matrix, in which elongate or spindle-shaped cells are em- 

 bedded at pretty wide intervals apart. Its remarkably cartil- 

 age-like, clear aspect is due to the large amount of clear sub- 

 stance between the cells already mentioned. This peculiar 

 structure undoubtedly belongs to the skin, yet it is a most 

 singular type of dermal tissues, probably not found in any 

 type of vertebrates except fishes. It is most largely de- 

 veloped over the opercles or gill-covers and over the region 

 in front of and behind the eye in the shad. In fact the eye- 

 ball seems to be partly embedded in it. Its great transpar- 

 ency, although covering in the eye in large part and even en- 

 croaching at times upon the pupil, would not interfere with 

 the lines of vision either backward or forward. This trans- 

 parent tissue thus forms a sort of imperfect anterior and 

 posterior immovable transparent eye-lid, thus also affording 

 a not inconsiderable amount of protection to the 'eye-ball 

 without obstructing vision. Such an arrangement of a trans- 

 parent anterior and posterior eye-lid is met with in a good 

 many other types of fishes in which the microscopical struct- 

 ure is probably very similar. At any rate, whatever its func- 

 tion , its histological structure would afford an interesting field 

 for more exact histological observation. 



The lateral line system of the front of the head of the sea- 

 bass is also exceedingly complex and also seems to be em- 

 bedded in a peculiar kind of tissue. These types, the shad 

 and sea-bass, therefore present complications of the lateral 

 line system over the head and the investing"" tissues, which 

 would well repay further and more elaborate biological and 

 microscopical investigation than has been bestowed upon 

 them in this brief note. 



Mr. May brought up the subject of a place for the next 

 meeting of the Society and moved that the place be now de- 

 cided on. 



Mr. Blackford seconded the motion and named Wash- 



