ALGOLOGICAL NOTES 81 
There is no essential family difference between a Mesotenium and 
a Closterium. The fact that there is no actual line of junction 
between the new and sis old half-cells in ie Spiroteniz is a 
little importance, since the development of the new half-cells 
e same as in Clostertwm* and other escitna. Olniiaiiat’ 
phylogeny of Desmids as a whole, I am quite unable to support 
i establishment of the family Messtatiiadae proposed by 
man 
"XVI. —Two New Species oF ULOTHRIX. 
Ulothrix spiroides, sp. n U. sublimnetica, inter alias 
iba libere ae ; filis angustiseimis et brevibus, in spiram 
axam vel laxiusculam plus minusve 
regulariter eset tela cellulis diametro 
44-81-plo longioribus; cellulis apicali- 
bus obtusis; chromato phora parietali 
or, unilaterali, sine 2S peers e. 
Crass. fil. 1; diam. spir. 17-23 p, 
fractibus 23-35 pp inter se distentibus. B 
(Fig. 5.) 
Hab. Abundant in the lakes at Great 
Barr Park, Staffordshire. (Oct. 1911.) 
his minute Ulothriz occurred in 
great wagers in the above-mentio ned A 
Alga = SS — contorta 
poe ‘a is most 
Statfordehis plants differ 50 sei 
important respects from Chodat’ S species 
that it is impossible to regard them 
other than distinct. In the first es 
there is a complete absence of the wide Fic. 5. ene os sriroides 
’ mucous sheath which appears to be a A-C, three filaments, x 9 
Vi ee en bos ee rai PT gee Pm Pee ss chloroplasts said only 
The cells are also of less diameter, and shown in 
* Consult B. F. Lutman, “Cell and Nuclear Division in ea sheet 
Botan. Gazette, li. 1911. Cell-division in Mesotenium caldariorum is exactly 
similar to that described and figured by Lutman as as occurring in Mietertites 
Ehren acd a Co: fig. 8, F-I, with -Lutman’s figures 3-8 on plate xxii. of 
his pape +R. Chodat in Bull. de l’Herb. Boiss. 1900, p. 10, fig. 20. 
