STAURA STRUM. 1 1 1 



IRELAND. Dublin and Wicklow (Arch.). Lough 

 Derryadd, Armagh ! Skady and Kam's Islands, Lough 

 Neagh ! 



Geogr. Distribution. Germany. Eoumania. Italy. 

 Sicily. Norway. Sweden. Finland. Faeroes. Japan. 

 E. Africa. United States. Newfoundland. 



The relative length of the processes seems to be very variable 

 in this species, and there also seems to be considerable variation 

 in the strength of the granulation. After carefully studying 

 specimens from Yorkshire, Prof. G. S. West decided that the 

 relatively broader individuals with longer processes are usually 

 more strongly developed as regards the spines, whilst specimens 

 with short processes have their emarginate warts very much 

 reduced (see 'Variation Desm.' 1899, p. 393). Some specimens 

 have much in common with St. margaritaceum var. ornatum 

 Boldt. 



116. Staurastrum neglectum G. S. West. 

 (PL CXLII, figs. 16-18.) 



St. income var. ft Ralfs, Brit. Desm. 1848, p. 134, t. 34, f. 8, b, c, and d ; 



Cooke, Brit, Desm. 1887, p. 168, t. 64, f. 5. 

 St. hexacerum var. /3 Wittr. Gotl. 6l. sotv. Alg. 1872, p. 52 ; Roy & Biss. 



Scott. Desm. 1893, p. 21 ; West & G. S. West, Alg. S. England, 1897, 



p. 495. 

 St. neglectum G. S. West, Alg. Yan Yean, 1909, p. 70, t. 3, f. 12. 



Cells small, Ij-lj times broader than long, including 

 the processes ; constriction extremely small, scarcely 

 visible ; lower part of semicell shortly cylindrical, upper 

 part incudiform, apex of semicell convex, angles pro- 

 duced to form attenuated processes, provided with 

 minute granules arranged in horizontal series. Vertical 

 view triangular, " body : small, sides concave, angles 

 produced into fairly long, attenuated, straight, or 

 slightly curved processes, which are provided with 

 6 or 7 rows of minute denticulations ; processes some- 

 what dilated towards their apex, which is tipped with 

 3 minute spines. Cells usually twisted, the processes 

 of one semicell alternating with those of the other. 



Zygospore spherical, with slender processes 2 or 3 

 times forked at the apex, and with slightly inflated bases. 



