q 
506 MR W. WEST AND MR G. S. WEST ON 4 
a 
leviter constrictz, sinu subangusto-lineari; semicellulis oblongo-semiellipticis, lateribus 
levissime biundulatis, angulis rotundatis, apicibus convexo-truncatis cum processibus ' 
connexis brevissimis ; inter cellulas lacunis nullis; a vertice visze triangulatee, lateribus 
subrectis vel levissime convexis, angulis leviter subproductis et rotundatis. 
Long. 26-27°5 » ; lat. 32°5-34; lat. isthm. 25-27 »; lat. apic. 21-22 nu. 
Hab.—Loch Fadaghoda, Lewis, Outer Hebrides. 
This Desmidium occurred abundantly along with D. coarctatum, var. cambricum, 
in the plankton of the above-mentioned lake. It is distinguished from D. Swartai, 
Ag., by the proportionately greater length of the cells, and by the shortened and more 
rounded lateral angles of the semicells. The vertical view is likewise more robust, — 
and the sides are slightly convex (not concave as in D. Swartzit). 
Although D. occidentale occurred in quantity in Loch Fadaghoda, we have never 
seen it from any other locality. In none of the specimens is there any trace of a space 
between the apices of contiguous cells. 
It may also be compared with D. Bengalicum, Turn. 
Genus Gymnozyga, Khrenb., 1840. 
39. G. moniliformis, Khrenb., var. gracilescens, Nordst., in Botaniska Notiser, 1880, 
p. 119; in Wittr. & Nordst., Alg. Hasic., No. 367. 
Hab.—Loch Fadaghoda, Lewis, Outer Hebrides. 
This variety has not previously been recorded for the British !slands. 
Order PROTOCOCCOIDE4S. 
Family VotvocacE&. 
Genus Pleodorina, Shaw, 1894. 
40. P. californica, Shaw, in Botan. Gazette, xix., 1894, pp. 279-283, t. 27 ; Kofoid, 
in Bull. Illinois State Lab., v., 1898, p. 291. | 
Diam. colon. 90-1134; diam. veg. cell. 6°5-7°5 «; diam. gonid. cell. 13°4-165 4 
(PING, fic: 14): 
Hab.—Loch Fadaghoda, Lewis, Outer Hebrides. 
Among a quantity of Hudorina elegans which occurred in Loch Fadaghoda, 
several colonies were observed which we think correctly placed as Pleodorina califor- 
nica, Shaw. 
They differed from Hudorina in the outward form of the colony, which was ellipsoid 
with slight posterior lobes, whereas all the colonies of Hudorina were globular. There 
was also a well-marked distinction into vegetative aud gonidial cells, the latter being 
more than twice the diameter of the former. 
The specimens observed did not strictly agree with the characters of either of the 
two known species of Pleodorina. The number of cells in the colony was 32 in every 
