WELWITSCH's AFRICAN FRESHWATER ALG.E, 177 



coacavis, augulis in processus breves (paullo longiores quam latiores) 

 latos truncato-emargiuatos producfcis, granulo iutra basin processus 

 uniusciij usque, processibus unius semicellubi^ cum iis alterius al- 

 ternantibus ; membraua glabra. Long. 15 /x ; lat. 15 /x ; lat. 

 isthm, ji. 



Huilla. Inter Utriculariam, Morro de Lopollo ; April 1860. 

 No. 179. 



Tliis at first sight reminds one of iS'. inconspicuum Nordst. ; but 

 it differs in its much more robust processes, which are directed 

 horizontally, and have not the nodulose swelling on the under side. 



4. S. huillense, sp. n. (tab. 3G8, fig. 17). S. minutum, 

 1 j-plo latius quam longius, profundissime constrictum, sinu lineari ; 

 seraicelluhe late oblongo-rectangulares, angulo inferiori uuoquoque 

 cum spina brevi convergenti, verruca emargiuata lateri uniquique, 

 angulo superiori emarginato (subfurcato, — dente superiori lougiori) ; 

 a vertice visa? triangulares, lateribus leviter concavis, angulis sub- 

 truncatis, angulus unusquisque verrucam tridentam gerens. Long, 

 sine spin. 15 /x; lat. 20 /x; lat. isthm. /x. 



Huilla. In paludibus exsiccandis ; April 1860. No. 170. 



5. S. egregium, sp. n. (tab. 369, fig. 12). S. parvum, circiter 

 1^-plo longius quam latius, profunde constrictum, sinu aperto 

 acutangulo; semicellulte subrectangulares, marginibus lateralibus 

 et apicibus rectis, angulis leviter rotundatis, angulis superioribus 

 cum procossu brevi lato bifurcato, angulis inferioribus verruca lata 

 emarginata instructis; a vertice viste triangulares, lateribus leviter 

 concavis, spiuis tribus ad angulos late truncatos (spina singula ad 

 angulum unumquemque et spina mediana validiori) ; membrana 

 glabra. Long, sine spiu. 21-23 /x, cum spin. 20-27 /x ; lat. sine 

 spin. 15-17 jt., cum spin. 21-22 /x ; lat. isthm. 7*5-9'5 /x. 



Huilla. In uligiuosis editioribus prope Humpata, Empalanca 

 ct Lopollo ; May 1800. No. 15. Etiam Morro de Lopollo; May 

 1860. No. 182. 



This Staumstrum belongs to the same section as S. qundri- 

 cnrnutum Roy & Biss. and S. (jemelUparHm Nordst., but is very 

 distinct from either. Each of the three angles of the semicells is 

 more or less quadrate with a short bifurcate process at the two 

 upper corners, with an emarginate wart at each of the lower 

 corners, and a short stout spine between the two emarginate warts. 



0. S. tridens-Neptuni, sp. n. (tab. 369, fig. 7). S. mediocre, 

 tam longum quam latum (sine spinis), profunde constrictum, sinu 

 aperto acutangulo ; semicellubD late oblonga), apicibus rectis, mai>- 

 ginibus lateralibus leviter convexis, latere ventrali inflato (marginibus 

 sinus rectis), spinis validis longis acutis tribus ad marginem lateralem 

 unumquemque, spina centrali horizontali, spinis lateralibus diver- 

 gentibus ; a vertice viste semper pentagona3, lateribus levissime 

 concavis, spinis validis tribus ad angulos acutos verticaliter dis- 

 positis. Long, sine spiu. 31-5 //. ; lat. sine spin. 31 //-, cum spin. 

 58 /x ; lat. isthm. 15'5 /x. 



Huilla. Freq. in paludibus exsiccandis ; April 1860. No. 170. 

 Etiam inter Utriculariam, Morro de Lopollo ; April 1860. No. 179. 



Journal of Botany. — Vol. 35. [May, 1897-] n 



