ALGL22 OF WEST IRELAND. 183 



Long, cum proc. 33 /x ; long, sine proc. 14 p ; lat. cum proc. 

 27*5-30^ ; lat. isthm. 5 fi. 

 II. Upper Lake of Killarney. 



tG2. Staxjhastrttm contobtum, D^Zp., var. psetjdotetracerum, 

 Nord. (Fr. Wat. Alg. of New Zeal. Sf Austr. p. 37, tab. 4. fig. 9.) 

 L Lakes near Recess. 



ttG3. S. natator, nov. sp. (PL XXIIL fig. 14.) 



S. mediocre, circiter duabus partibus longius quam latius, modice 



constrictum ; incisura parva et aperta ; semicellulsB subquadran- 



gulares, marginibus lateralibus leviter crenatis, verrucis mucro- 



natis magnis tribus ad polos ; angulis superioribus productis in 



processibus dentieulatis divergentibus, apice tridentatis ; a vertice 



visae ellipticae, processibus productis ad polos; projectione pro- 



minente truncata centrali in medio, seriebus duabus verrucarum 



subquadratarum intra marginem ordinate's; a latere vis® sub- 



rotundae projectione mediana, processu conspecto inter verrucas 

 binas. 



Long, sine proc. 38*5 /j. ; long, cum proc. 67 p ; lat. ad bas. 

 semicell. 20 /x ; lat. apic. sine proc. 25 /x ; lat. cum proc. 75 /z ; 

 long. proc. 30-32-5 // ; lat. isthm. 12'5 // ; crass. 21-5 ft. 



I. Derryclare Lough. 



Compare with S. brachiopro?ninens, Boerg. (Desm. Brasil. 

 p. 952, tab. 5. fig. 52), and S.paradoxum, Meyen, viLT.fusiformc, 



Boldt. (Siber. Chloroph. p. 118, tab. G. fig. 37). 

 ttGi. B. Archerii, nov. sp. (PI. XXIIL fig. 15.) 



S. magnum, subduplo longius quam latius (sine processibus), 

 emarginatum ad medium ; semicellulse breviter cuneata), apice 

 convexo glabratoque, marginibus lateralibus subrectis, angulis 

 superioribus in processibus longissimis gracilibus radiatis denti- 

 culis productis, subcurvatis extrorsum, apicibus tridentatis; a 

 vertice conspecta) circulares, processibus radiatis denticulatis, 



• * m 



apicibus tridentatis ; membnina glabra. 



Long, (sine proc.) 69-78 /* ; lat. cum proc. 130-140 /i ; lat. 

 sine proc. 43-48 *x ; max. long. proc. 50 p ; lat. isthm. 21 /i. 



I. Ballynahinch ; Derryclare Lough. 



The vertical view of this species is similar to that of St. verti- 

 cillatum, Arch, (of which I have authentic figures), but the 

 front view is quite different. 



ura 



BOTANY, VOL. XXIX. P 



