278 
Transactions of the Society. 
for the large and most varied gatherings which he made his chief 
object during two summer holidays spent in this rich district ; it is in 
fact entirely owing to his gatherings that I have been induced to 
write this paper, and as he has also rendered me the most valuable 
help during the preparation of this article, I tender him my hearty 
thanlxs. His gatherings were made at many places, the following 
being the chief : — Snowdon, Llyn Idwal, Llandudno, Llyn Ogwen, 
Bethesda, Bettws-y-coed, Llanfairfechan, Penmaenmawr, Twll Du, 
Aber, and the following places in Anglesea : — Llyn Coron, Bodorgan, 
Newborough Babbit Warren, Maltraeth Yard, and Holyhead. Of 
course he could not resist also making a large series of gatherings at 
that happy hunting ground first investigated by Mr. Wills, namely 
Capel Curig, which is certainly about the richest locality ever found 
in Britain. 
The species mentioned for Twll Du were collected at an elevation 
of 2000 feet. 
The gelatinous investment noticed in many species was especially 
conspicuous in Gosmarmm Scenedesmus Delp., Stcmra, strum Sebaldi 
Keinsch, and S. longis'pinum Bail., the investment round the latter 
being relatively larger than, and quite as conspicuous, as that of 
S. tumidum Breb. 
The gathering at Llyn Coron proved to be the richest in diatoms ; 
it was chiefly from washings of Elatine Hydropiper and E. hexandra. 
Some rare species were obtained from washings of Dicranum fulvel- 
lum (Dicks.) Sm. and Nardia emarginata Ehrb., which were collected 
at over 2000 feet on Snowdon. 
Fig. 17. — Docidium elongatum nov. sp. 
„ 18. — Cosmarium orUmlatmi Ralfs. 
„ 19. — „ isthmium nob. 
„ 20. — Staumstrum spiniferwn nov. sp. 
„ 21. — Xanthidium cristatum Breb. var. spinuliferwn nov. var. 
„ 22. — Staurastrum controve7'sum Breb. var. 
23. — Clostei'iim striolatum Ebrb. forma recta. 
Plate VI. 
Fig. 24. — Penium spit'ostriolatum Bark. 
„ 25. — Cosmarium teti'aophthalmum (Ktz.) Breb. var. subrotundum nov. var. 
„ 2(3. — Euastrum verrucosum Ehrb. var. 
,, 27. — Staurasti'uin denticulatum (Nag.) Arch. 
„ 28. — „ dubium nov. sp. 
„ 29. — Docidium sp. 
jiO. — Cosmarium coelatnm Ralfs. var. hexagonum nov. var. 
,, 31. — „ controversiim nov. sp. 
32. — Staurastrum margaritaceum Meneg. var. 
„ 33. — Euastrum crassum Ktz. var. 
„ 34. — Micrasterias Jenneri Ralfs. var. simplex nov. var. 
„ 35. — Staurastrum proboscideum Breb. var. subglabrum nov. var. 
„ 3<3. — „ cumbricum nov. sp. 
37. — „ „ „ var. cambricum nov. var. forma 7iiinor. 
.. 38. — Xanthidium Bt'cbissonii Ralfs, forma. 
,, 39. — „ aculeatum Ehrb., forma. 
40. — Arthrodesynus octocotmis Ehrb., var. 
