274 MYRIOZOID^. 



Not unfrequently the interstitial spaces between the 

 lines of cells are punctured, the perforations being narrow 

 and elongate. Small tubules are also sometimes present 

 in the same situation, which I believe to be the rudi- 

 mentary stage of the dwarf cells that bear the ooecia, and 

 of the other secondary cells associated with them. 



In a variety from Santa Cruz the cells are much pro- 

 duced and attenuated below, with massive transverse 

 ridges, one of which projects immediately beneath the 

 mouth ; the interstices are strongly punctured. (Plate 

 XLV. fig. 3.) 



Habitat. On shells, stones, Laminaria saccharina and 

 other Algae, stems of Sertulariidse, &c., from between 

 tide-marks to deej) water (between 62 and 72 fathoms, 

 coast of Antrim ; 100 fathoms, Greenland) . 



Localities. Universally distributed on the coasts of 

 Great Britain and Ireland. 



Geographical Distribution. Cosmopolitan. Australia 

 (vars. cornuta and tuberculata) ; New Zealand (T. H.) : 

 East Falkland Islands, 4-10 fathoms (Darwin) : Cape of 

 Good Hope (Harvey) : Kerguelen^s Island, three vars. 

 (Busk) : Natal, var. cornuta (W. Gates) : California, 

 normal and var. cornuta (Dr. Sinclair) : Anticosti and 

 Mingan Islands (Packard) : Bahusia to Spitzbergen and 

 Greenland, 3-30 fathoms (Smitt) : Davis Strait, off Fre- 

 derickshaab, 100 fathoms (Wallich) : Nova Zembla, 2-20 

 fathoms (Stuxberg and Theel) : oflF Bear Island (Dutch 

 Arctic Exped.) : Boscoff, on red Algae and Chondrus 

 (Joliet) : France, S.W. (Fischer) : Santa Cruz, var. (Miss 

 Jelly). 



Range in Time. Cor. Crag, Sutton, on shell (S. W.) : 

 Bed Crag (A. Bell) : Scotch Glacial deposits (Geikie) : 

 Postplioccne deposits, Canada (Dawson). 



