MASTIGOPHORA HYNDMANNI. 281 



Localities. Form a : — Coast of Antrim (Hyndmaii) : 

 oflF the Deadman, coast of Cornwall^ 60 fathoms (T. H.). 

 Form (3 : — Shetland, very abundant, 80-170 fathoms 

 (A. M. N.) : Guernsey (T. H.). 



Geographical Distribution. Red Sea (Savigny) : 

 Madeira (J. Y. J.). 



Distribution in Time. Coralline Crag, on Tellina 

 (Searles Wood) : Mitteloligocan Tertiary beds, at Sollin- 

 gen (Reuss) : Older Pliocene, Castrocaro (Manzoni) . 



Mastigophora Hyndmanni, Johnston. 

 Plate XXXVII. figs. 3-6. 



Lepralia Hyndmanni, Johnst. B. Z. ed. 2, 306, pi. liv. fig. 6 : Busk, B.M. 



Cat. ii. 74, pi. Ixxxvii. figs. 5-8. 

 Herentia HyndxMAnni, Gray, B.M. Ead. 122. 

 HiPPOTHOA poeosa, Simtt, Floridan Bryozoa, pt. ii. 41, pi. vii. fig. 158. 



ZocBcia ovate or rhomboid, broad, flat, smooth, and often 

 with a row of punctures round the edge, or coarsely 

 punctate over the entire surface, bordered by a raised 

 line ; orifice arched above, straight below, slightly 

 notched at each side above the inferior margin, and with 

 a central sinus ; peristome forming a broad, thickened 

 border round the upper part of the orifice; a long 

 vibraculum, springing from a distinct vibracular cell, 

 on one side, a little below the mouth. Ooecia small, 

 arcuate, flattened in front. 



Colonies forming small, flat, inconspicuous patches. 



Range of Variation. M. Hyndmanni exhibits a very 

 interesting series of varieties, embracing forms which, in 

 the hands of some systematists, would probably obtain 

 specific rank. Indeed Smitt has separated one of them, 



