194 C. F, LASERON, 
most other species of Fenestella. There are usually three 
in the space of one fenestrule, allowing an additional one 
for the width of a cross-bar. 
Measurements:—In 10 mm. longitudinally, 11 cross- 
bars; in 10 mm. transversely, 18 branches. Length of 
fenestrules °6 to °7 mm., width °2 to ‘3 mm. 
Locality and Horizon:—Branxton (Upper Marine Series). 
Remarks:—I believe I have identified, with as little 
doubt as possible in the absence of the type, Lonsdale’s 
species, originally described from Tasmania. It is here 
again figured, as all the previously published figures are 
very poor and of little aid in recognition. De: Koninck 
synonymises F’. fossula under F. plebeia McCoy,* and 
records the latter species from the Carboniferous rocks at 
Glen William, but as pointed out by R. Htheridge junr.,? 
F. fossula differs in being relatively much smaller and finer, 
with the branches closer. Whether de Koninck undoubtedly 
received F. plebia from Glen William, it is not within my 
power to contradict or confirm; but as this author’s 
synonymy of the two species is now held to be invalid, and 
the specific rank of F. fossula maintained, the Australian 
occurrence of F.. plebeia is, under the circumstances, very 
much open to doubt. 
FENESTELLA INTERNATA (?) Lonsdale.’ (Pls. X, fig. 2, XI.) 
To F. internata is referred provisionally a form, the 
known characters of which agree fairly well with Lonsdale’s 
description. Unfortunately the celluliferous surface is not 
visible in the one specimen available, and its correct 
identity must remain at present in abeyance. 
The known characters of this specimen are:—Branches 
thin, separated from each other by about twice their width, 
‘ De Koninck, (6) p. 130 —1382. 
2 R. Etheridge, junr., (18) p. 227, pl. 9, figs. 4 and 5. 
