PHAOPHYCEA 95 
of all. They are-long, filamentous, consisting of a 
single series of loculi, and originate from the base of 
assimilative filaments. In Zeptonema certain of the 
upper cells of the filaments become the mother-cells 
of the plurilocular sporangia. These cells bulge out 
laterally and divide into 3-6 transverse loculi, each 
with one or two gametes. In Halothriz the matter 
is more complex. The mother-cell divides up into a 
considerable number of cells, of which those at the 
periphery grow out into rows of loculi which contain 
each a single gamete. Giraudia, of which the gametes 
have been observed to conjugate, possesses two sorts 
of plurilocular sporangia. The one kind are tapering 
filamentous bodies of several rows of loculi, otherwise 
resembling those of Hlachista in origin. The other 
kind are of singular appearance, originating from the 
cells of the assimilative filaments by transverse and 
radial divisions, and forming clusters of ovate pluri- 
locular sporangia, each of several rows of loculi. This 
second kind approaches the Halothria type in general 
character. 
The Geographical Distribution of the Hlachistacece 
is general, but most of the forms are from the North 
Atlantic. Slachista, Halothriz, Giraudia, and Lepto- 
nemea are British. 
The genus Myriotrichia (North Atlantic), of which 
M. claveformis is British, stands in a somewhat 
isolated systematic position. It has been placed 
with the forms ranged under Hneeliaceee, and in a 
separate position by itself as the type of an order 
Myriotrichiacec, while its relationship with Hlachis- 
tacee is not denied, Further research, not so much 
