124 Rev. W. Smith on Deposits of Diatomaceous Earth. 
as an acute observer in another department of natural history is 
not unknown to the readers of the ‘ Annals”), is a large and hand- 
some species intermediate between HE. zebra and E. granulata, 
but distinguished from both by its stouter habit, the regular 
convexity of its dorsal outline, and its rounded ends. 
description in a note*. 
+Epithemia Musculus. 
4r zebra. +Gomphonema acuminatum. 
aR ocellata. +—— constrictum. 
+—— gibba. geminatum. 
+ turgida. +Navicula nobilis. 
granulata. T major. 
Hyndmanii. +—— viridis. 
+Himantidium pectinale. + sphzerophora. 
Fragilaria virescens. + radiosa. 
capucina. —— nodosa f. striata. 
+Cyclotella operculata. —— binodis. 
minutula. —- lata. 
+Melosira orichalcea. — dicephala. 
+ arenaria. —— mesolepta. 
Campylodiscus noricus. a; elliptica. 
Surirella splendida. firma. 
+—— bifrons. tT attenuata. 
+ Solea. +Stauroneis Phcenicentron. 
+—— elliptica. punctata. 
+Synedra capitata. lanceolata. 
‘i biceps £. recta. cardinalis. 
T ulna. di lineolata. 
sigmoidea. amphicephala. 
+Cocconeis Pediculus. — Platystoma. 
+Cymbella Ehrenbergi. 
+Cocconema Cistula. 
+Amphora ovalis. 
cuspidata. Tabellaria fenestrata. 
+Cocconema lanceolata. ventricosa. 
ap cymbiformis. 
ladda 
It is evident from the above that neither of the deposits found 
can with strictness be termed fossil ; that they are simply the 
siliceous coverings of species, the greater number, if not all, of 
which, still inhabit the waters of the lake, having required no 
doubt a lengthened period for their accumulation, but still one 
comparatively recent, and which cannot be regarded as conferring 
a fossiliferous character on the deposit itself. 
In the ‘ Magazine of Nat. Hist.’ for July 1839, an interesting 
description of an “ Infusorial” earth found on drainmg Lough 
Island-Reavey, co. Down—is given by Dr. Drummond of Bel- 
fast : I have been enabled by the kindness of W. Thompson, Esq. 
of that town to compare this deposit with those I have here 
noticed. Although occurring under very similar circumstances, 
* Epithemia Hyndmanii, W. Sm. EE. major, a latere secundario valde 
et eequaliter convexa, apicibus obtusissimis rotundatis non recurvatis, striis 
transversalibus moniliformibus vix convergentibus: a latere primario ob- 
longa medio valde dilatata. Long. s$5-7}5 uncie. 
