264< MESSES. W. WEST AND G. S. WEST ON 



The nearest species to this is S . franconicum , Reinscli (Algenfl. Pranken, p. 158, t. 12. 

 fii^. 3), from which it differs considerably. A good many examples of this were seen, 

 all of which were 5-rayed. Compare also with ^S'. zonakwi, Boerg. (in Vidensk. Meddel. 

 1890 (1891), p. IG, t. 5. fi-. 48). 



113. Staueastrum bicoronatum, IS". L. Johnson, in Bull. Torr. Bot. Club, xxi. (1891) 

 p. 290, pi. 211. fig. 9. 



Yar. siMPLicius, noY. var. (PI. XVII. fig. 6.). Var. semicellulis a vertice visis sine 

 aunulo spinarum parvarum furcatarum intra marginem; apicibus processuum 

 emarginatis et bidenticulatis (non trifidis) ; processibus unius semicellula^ cum iis 

 alterius alteroantibus. 



Long. 14-5 ;i ; lat. s. proc. circ. 9-5 /^i, c. proc. 32-34'5 /n ; lat. isthm. 6 ^i. 



We had this variety described as a species in manuscript some time before Johnson's 

 paper appeared ; it differs from his sufficiently to make a well-marked variety. 



144. S. iNCisuM, Wolle, Desra. U.S. p. 132, pi. 41. figs. 12-14. 



Yar. EFFiGL'RATUM, nov. var. (PL XVII. fig. 7.) Yar. semicellulis a vertice visis 

 incisurii inter processus apertiore, processibus ornatis cum processu brevi prope 

 basin utrobique. 

 Long. 25 ^t ; lat. c. proc. 42 /u ; lat. isthm. 9 n. 



Compare with ^S'. ornatimi, W. B. Turn. (Preshw. Alg. of E. India, p. 115, t. 13. fig. 28* ; 

 S. margaritaceum, Ehrenb., f. ornata, Boldt. in Ofvers. Sv. Vet.-Akad. Porh. 1885 (1886), 

 n. 2, p. 115, t. 5. fig. 27). 



145. S. LOGIMUM, nov. sp. (PI. XYII. fig 8.) S. mediocre, duj^lo longius quam latius 

 (sine processibus), modicc constrictum ; semicellulse subquadrangulares, iateribus 

 l)icrenatis crena inferiore majore et subemarginata, apicibus levissime concavis, 

 angulis superioribus in processus longos tenues leviter divergentes et subflexuosos 

 productis, subnodulosis basin versus et subundulatis apicem versus, apicibus cum 

 dentibus quattuor divergentibus sed incurvatis ; a vertice visa? triangulares 

 laterilms subrectis, angulis in processus longos productis; cum basi semicellularum 

 trigona Iateribus concavis et angulis truncato-emarginatis ; membrana glabra. 



Long. s. proc. 25-27 /t ; lat. s. proc. 13-14 n, c. proc. 75-80 ^l - lat. isthm. 7-7 /u. 

 This seems a characteristic species, of which only three examples have been seen. 



146. S. PARADOXLM, Meycu ; Ralfs, Brit. Desm. p. 138, t. 23. fig. 8. 



Yar. oscEOLENSE, Wolle, Alg. U.S. p. 45, pi. 59. figs. 8, 9. Porma minor. (PI. XYIL 



fig. 9.) Porma seraicelluhs a vertice visis triangulares. 

 Long. s. proc. 15 ^i, c. proc. 31 ^t ; lat. s. proc. 9-5 /(, c. proc. 42 ^i ; lat. isthm. 45 fx. 

 Pig. 8, pi. 59 (Wolle), does not represent a front view; it is much tilted and incorrectly 

 drawn. 



