W. WEST AND G. S. WEST: ALGA- !■ I. Ok A Ol' YORKSHlkE. I 25 



597. Tetraedron incisum Lageih. 

 N.W. — Jervaulx Abbey. 



N.E. — Pilmoor, near 'I'hirsk. 



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

 N.E.— Strensall. 



599. Tetraedron decussatum (Reinsch. 1867) Nob. 



[Syn. Folyedriuiii decussatum Rcinsch, 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. enorme, but it is certainly distinct from any forms of T. enorme 

 we have yet come across. 



Diam., 46-55 \^.. 



This species has not previously been recorded for the British 

 Isles. 



Genus CERASTERIAS Reinsch, 1867. 



600. Cerasterias longispina (Perty 1852) Nob. 

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



N.W.— Mickle Fell. 



601. Cerasterias rhaphidioides Reinsch, 1867. 

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



Sub-Family CHARACiE.ii. 

 Genus CHARACIUM A. Br., 1849. 



602. Characium ornithocephalum A. Br., 1855. 

 Mid W. — Baildon. Boston Spa. 



603. Characium longipes Rabenh. 

 N.E. — Pilmoor, near Thirsk. 



604. Characium Sieboldi A. Br. 

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

 Mid W.— Near Ilkley (Miss J. Town). 



605. Characium minutum A. Bl 

 S.W.— ^Vibsey (vii. 1896). 



