DIATOMS AND LOBSTER REARING “19 
SESSIONAL PAPER No. 38a 
Nitzschia closterium W. Sm. 
Acnanthes subsessilis Kutz. 
Fragilaria fenestrata Grun. 
Amphora quadrata Breb. 
Synedra affinis Kutz. 
Coscinodiscus excentricus Ehr. 
Grammatophora angulosa Grun. 
Chaetoceras cinctum Grun. (?) 
Pleurosigma affine Grun. 
Nitzschia panduriformis var. minor Grun. 
Actinoptychus undulatus Ehr. 
There were also many individuals of the protozoan, Peridinium lenticulare Ebr. 
Scrapings from the carapace of a mother lobster, from which larve were hatched, 
gave a few diatoms, but the plant growth on the creature was almost entirely Ecto- 
carpus, the diatoms being merely entangled in this alga. 
Inemophora Lyngbyei (Kutz) Grun. 
Cocconeis scutellum Ebr. 
Grammatophora marina Grun. 
Scoliopleura tumida Grun. 
While the above were sufficiently numerous, to infect the larve with diatoms, 
Iicmophora in particular, the numbers which accumulated on the larve could not be 
accounted for by drifting or swimming forms. The almost pure growth of Licmo- 
phora, its firm attachment to the larve, and the increase in diatoms day by day, 
when exposed to sunlight, all point to their rapid reproduction in sitw, as the cause 
of their great numbers. Another evidence was the fact that the plankton net, towed 
in the water about the raft which supported the rearing boxes, collected compara- 
tively few Licmophora, but many individuals of other species. The species named 
below were found to be plentiful in about the order they are named :— 
Chaetoceras decipiens Clave. 
Cocconets scutellum Ehr. 
Pleurosigma elongatum. 
P. angulatum W. Sm. 
Paralia sulcata (Ehr.) Clave. 
Fragillaria hyalina (Kutz) Grun. 
Nitzschia longissima (Breb) Ralfs. 
Chaetoceros dichaeta. 
Actinoptychus undulatus Kutz. 
Licmophora Lyngbyei (Kutz) Grun. 
Amphora quadrata Breb, 
Attached to the timbers of the rafts, and to the ropes by which the structure was 
anchored, was a thick growth of Homoecladia capitata H. L. Sm. Its brown masses 
showed a definite relationship to the aerated surface waters, being entirely lacking 
where the ropes reached down a few feet from the free atmosphere. The plankton 
net collected also many specimens of Peridinium lenticulare Ehr. and P. reniforme, 
while Ceratium tripos Nitsch, was not rare, and the Silico-flagellate, Distephanus 
speculum (Epr.) Haeckel, was common. 
From the waters of St. Mary’s bay, in front of the intake pine of Long Beach 
pond, the plankton-net collected a few specimens of Licmophora Lyngbyei (Kuntz) 
Grun, but the catch was very rich in the common Bay of Fundy forms :— 
38a—2 
