NEW TO BRITAIN IN 1880. 211 



EXPLANATION OF PLATES XIIL TO XVI. 



PLATE XIIL 

 Fig. A. — Types of Cosmariuni; a, Cosmarium 2)scudonitidulum Nord., 



with side and end views; I, Cosmarium camhricum, C. & W., with 



side and end views. 

 Fig. B. — Type of Xanthidium. X. antilopeum, Breb., with c, side view ; 



d, end view. 

 Fig. C. — Types of Arthrode^miis, e, A. convcrgens, Ehr., with end views; /, 



A. incus, Breb., with end views. 



PLATE XIV. 

 Figs. 1-3. — Staurastrum psevdArfurcigerum^ Eeinsch; 2, 3, end views. 

 Fig. 4. — Staurastrum furcigerumy Breb. ; 5, end view with four arms. 

 Fig. 6. — staurastrum arctisco/i, Ehr., 7, end view. 

 Fig. 8. — Staurastrum sexangulare, Buln. ; 9, end view. 

 Fig. 10. — Staurastrum o%)hi2ira, Land. ; 11, end view. 



PLATE X7. 

 Fig. 12. — Staurastrum aiiatinum, C. & W. ; 13, end view. 

 Fig. 14. — Staurastrum Schaldi, Eeinsch. ; variety j l5, end view. 

 Figs. 16, 17. — Staurastrum paradoxum, Mey., var. longipes; front and 



end views. 

 Figs. 18, 19. — Staurastrum cerades, Lund. ; 20, end view. 

 Figs. 21 to 24. — Supposed varieties of Staurastrum saxon'icum, Eeinsch., of 



which no end views have been obtained. 

 Fig. 25. — Staurastrum Brasilieiue, Nordst. ; 26, end view. 



PLATE XVI. 

 Fig. 27. — Staurastrum grar.de, Lund., Capel Curig form ; 28, end view. 

 Figs. 29-81. — Staurastrum megacanfhum, Lund.; 30, end view. 

 Fig. 32. — Staurasiriivi aristiferum, Ealfs. : 33, end view. 

 Fig. 34. — Staw-asfrum hrevispiua, Breb. ; 35, end view. 

 Fig. 3C). — Staurastrum avers7im, Lund. ; 37, end view. 

 Fig. 38. — Statirastrum iujlexum, Breb. ; front and end views. 

 Fig. 39. — Staurastru7?i. rriugsheimii, Eeinsch. ; 40, end views. 

 Fig. 41. — Staurastrum longispinum, Bailey; 42, end view. 

 All the figures drawn to an uniform scale of 420 diameters. 



