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Transactions of the Society. 
S. striolatum Nag. C., B. 
S. muricatum Breb. S., Do., A., D. 
va]’. ACUTUM nov. var. Fig. 14. 
Var. spinis brevibus (nec granulis), semicellulis trun- 
cato-pyramidatis. 
Long. 62-70 fx ; lat. 48-52 jx. 
This differs from the type in the acute though short spines in 
place of ‘‘ conic granules,” as well as in the trapezoid or truncately 
pyramidal semicells. S. 
This is the form I mentioned in The Freshwater Algae of N. 
Yorkshire ” (Journ. Bot., Oct. 1889), as being a distinct form noticed 
from several places. 
S. 'punctulatum Breb. Frequent. 
S. turgescens Not. F. 
S. fileolatum Breb. D., C. 
S. eapitidum Breb. D. 
S. Meriani Keinsch. P. 
All the specimens seen were 5-ended. 
S. alternans Breb. P., A. 
S. dilatatum Ehrb. C., P., Do. 
S. tumidum Breb. P., Do., D. 
S. aver sum Lund. Llanfairfechan. 
S. hrachiatum Ralfs. D. 
*S. scabrum Breb. C. 
S. tricorne (Breb.) Meneg. F., A., S., P. 
var. ^ Ealfs. 0. 
*S. Ilaahoeliense Wille. C. 
S. cyrtocerum Breb. Do. 
forma tetragona. Fig. 16. 
Forma a vertice tetragona. D., Do. 
S. inflexum Breb. S., A., F. 
S. polymorphum Breb. S., B., F. Llyn Idwal. 
*S. gracile Ealfs /3 nanum Wille. 0., S. 
S. paradoxum Meyen. A., B., Llandudno, 
var. longipes Nord. A. 
A form of this variety was seen with rather longer processes than 
usual. 
S. Ophiura Lund, forma nonaradiata. Fig. 15. 
Forma a vertice nonaradiata. 
End view with nine rays. 0. 
Of this beautiful species, two forms were noticed along with the 
type, one, a nine-rayed form, was seen several times, the other, a very 
long and slender armed one, measured 145 /x across the arms. Cooke 
