W. WEST AN13 G. S. WESt: ALGA-i'LORA Ol' VORKSHlUE. 125 



597. Tetraedron incisum Lageth. 

 N.W. — Jervaulx Abbey. 



N.E. — Pilmoor, near Thirsk. 



598. Tetraedron muticum (A. Br.), Hansg. 1888. 

 N.E.— Strensall. 



599. Tetraedron decussatum (Reinsch, 1867) Nob. 



[Syn. Polyedriuin deciisiiitum Reinsch, 1867]. 



N.E. — Pilmoor, near Thirsk. There were two forms agreeing 

 with those figured by Reinsch in Abhandl. Naturhistor. Gesellsch. 

 Niirnberg., Bd. 3, p. 79, t. ii., f. iii. and iv. (f. multilobum). 

 Hansgirg, in Hedwigia, 1888, p. 132, includes this species under 

 T. enor/iie, but it is certainly distinct from any forms of T. enormc 

 we have yet come across. 



Diam., 46-55 \>.. 



This species has not previously been recorded for the British 

 Isles. 



Genus CERASTERIAS Reinscli, 1867. 



600. Gerasterias longispina (Perty 1852) Nob. 

 [Syn. Polyedriuin longispinum (Perty), Rabenh. 1868]. 



N.W.— Mickle Fell. 



601. Gerasterias rhaphidioides Reinsch, 1867. 

 Mid \\ . — Pond, Boston Spa (iv., 1897). 



Sud-Familv Characie.e. 



GUNUS CHARACIUM A. Br., 1849. 



602. Gharacium ornithocephalum A. Br., 1855. 

 Mid \V. — Baildon. Boston Spa. 



603. Gharacium longipes Rabenh. 

 N.E. — Pilmoor, near Thirsk. 



604. Gharacium Sieboldi A. Br. 

 S.W.— Keighley (T. Hebden). Bowling. 

 Mid W.— Near Ilkley (Miss J. Town). 



605. Gharacium minutum A. Br. 

 S.W.— Wibsey (vii. 1896). 



