262 SEA-SIDE STUDIES. 



are continuous vnih. the caudal fin, into which tliey expand ; 

 that is to say, it has really but one fin on each side, 

 with a caudal expansion. Another peculiarity worthy of 

 notice is, that, in consequence of tliis union of the lateral and 

 caudal fins, the orifices through which issue the spermatozoa, 

 instead of opening directly in the integument of the body, 

 are openings in the fin itself ; as I have convinced myself by 

 repeated examination — a circumstance which leads us to 

 suspect that the "fin" is only a membranous expansion of 

 the integument, and not properly a fin. Other details, not 

 mentioned, and therefore, I presume, not present in the 

 specimens previously described, but which were constant in 

 those found at Scilly, are the double band of light yellow 

 granules forming three sides of a parallelogram about the 

 oesophagus, and two dark-brown irregular masses above each 

 oviduct. The hairs, or spines, are distributed over the fins 

 as well as over the body — an arrangement which has been 

 noticed by Krohn, who denies that they are setce at all, con- 

 sidering them to be merely epidermic processes. On what 

 grounds he so considers them, I am not informed ; but I 

 entirely concur with him, because I find these su2)23osed setw 

 veiy rapidly undergo decomposition, which would not be the 

 case were they inorganic hairs or spicule. Let me conclude 

 these perhaps dry details with the remark that the delicate 

 layer of epidermis, composed of rounded cells — the existence 

 of which Krohn first disputed and then admitted — was visi- 

 ble in my specimens, although I mistook it for scales or scaly 

 epithelium ; and that I can confirm Huxley's statement of 

 the existence of a ciliated oviduct in the external part of the 



