DOUBTFUL SPECIES. 19 
figures, and come from the same locality as the type-specimen, it is very distinctly 
a polyzoon belonging either to Hippothoa or Stomatopora. H. M. Fischer has 
also stated that it belongs to the Bryozoa (‘ Recherches sur les Eponges perforantes 
Fossiles,” ‘Nouv. Archiv. du Mus d’Histoire Naturelle,’ 1868, p. 133). In Morris’s 
‘ Catalogue,’ 1854, p. 27, it is placed with the Amorphozoa under the genus Cliona. 
The original specimens are from strata of Caradoc age, at Desertcraight, 
Tyrone. 
58. Favosponaia Rutavent, Salter (MS.). 
1855. Brit. Pal. Fossils, pl. in, figs. 9, 9 a. 
The examples of this species are mere structureless casts of ovoid bodies, their 
surfaces are covered with indistinct, circular, or irregular depressions. Their true 
character is problematical ; there is no evidence to connect them with Sponges. 
The specimens thus named are from Upper-Ludlow strata at Benson Knot, 
near Kendal; they are now in the Museum of the Geological Society of London, 
and in the Jermyn Street Museum. 
59. IscHapites microvora, Salter. 
1873. Cat. Cambrian and Silur. Foss. Cambridge, p. 40. 
The specimen thus named is a fragmentary cast of some organism exhibiting 
rows of puncta on the surface of compressed shale. It does not show any resem- 
blance to Ischadites or allied forms. 'The original, now in the Woodwardian 
Museum at Cambridge, comes from Middle-Bala strata at Blaen-y-cwm, North 
Wales. 
60. MamMILLoPpoRA MAMMILLARIS, Aing. 
1850. Mon. Permian Foss., Pal. Soe., vol. iv, p. 12, pl. ii, figs. 3, 4. 
The type is a small rounded mass with mammillary elevations. The surface is 
entirely covered with very minute polygonal perforations, similar to those of the 
doubtful organism Solenopora compacta, Billings sp. (see ‘ Geol. Mag.,’ dec. in, 
vol. ii, p. 529). No other structure is shown. This is certainly not a Sponge. 
From shelly limestone (Permian), Humbleton Hill. The type is in the Museum 
of Queen’s College, Galway. 
