336 Prof. J. Wood Mason on the Geograpldcal 



margins of aperture tuberculatc. Intercellular surface covered 

 with tinoly tubercular ridj^es, whose terminations form the 

 maru;inal denticles. Non-eelluliferous asj)ect iinely j^ranu- 

 lar, faintly striate. Cells encroach irregularly on this face 

 (rlate IX. A/.s', tig. 5); and small apertures (hg. 4) seem to 

 represent aborted cells. 



Locality. — Gillfoot, Carluke ; Gair j Robroyston : in Upper 

 Limestone shales. 



The ornament of a very young branch (tig. G) has a curious 

 resemblance to that of Sulcorctipora. Figure 7 shows one of 

 the apertures at the margin of the non-celluliferous aspect, 

 and the wavy striai around it. 



The generic position of the fossil is uncertain. It is not a 

 PolyporOj since it is not reticulate. T/iamniscuSy King, shows 

 a tendency to reticulation; but the junctions are at small angles. 

 Synodadia presents the next step towards the Fenestella type. 

 If the gemmuliferous vesicles described by King are essential 

 to his TliamniscuSj this character is wanting in our species, 

 even in the best-preserved specimens. Longitudinal sections 

 show the cells starting from an imaginary axis, and reaching 

 the surface at various levels ; but the tendency to an arrange- 

 ment in transverse series, seen in fig. 2, is apparent. We 

 have not yet found the base of attachment. Meanwhile, 

 though strongly disposed to regard this fossil as a true 

 Hornera or a member of a closely allied genus, we think it 

 safer to leave it in the Palaeozoic genus ThajnmscuSj and to 

 name it Th.? liankmi, after the gentleman to whom we owe 

 the finest examples. 



XLIII. — Note on the Geographical Distribution of the 

 Temnocephala chilensis of Blnnchard. By Jajies Wood 

 Mason, Professor of Comparative Anatomy, Medical Col- 

 lege, Calcutta. 



Some months ago I received from Captain F. W. Ilutton, 

 Curator of the Otago Museum, Dunedin, New Zealand, a 

 series of specimens of the freshwater crayfish lately described 

 by him in this Journal under the name of Parcmephrops 

 setosus, and was astonished to find, in the sediment at the 

 bottom of the jar containing these crustaceans, numerous ex- 

 amples of this remarkable little Trematode (whicli owes its 

 generic name to the fact that the ce])halic end of its body is 

 divided by four fissures into five teiitacular processes, and 



