ry 
8 DEPARTMENT OF THE NAVAL SERVICE 2 
7 GEORGE V, A. 1917 
in considerable numbers in the surface plankton. and on March 20 they became very 
abundant, and continued to be so, with some occasional diminutions, until April 21. 
The appearance of these Balanus larve in large numbers was, accordingly, coincident 
with the vernal increase of the phyto-plankton, corresponding almost exactly with 
the increase of Biddulphia, Coscinodiscus and Fragilaria, and preceding slightly 
that of Thalassiosira. 
Malacostraca. 
‘ 
Of the remaining groups of Crustacea, relatively few representatives were 
observed, and only at rare intervals. Two examples of the Schizopod Thysanoéssa 
inermis (Sars) Hansen were taken January 1, both belonging to the variety Rhoda 
of Hansen, who finds intermediate stages between the forms described as Rhoda 
inermis and Thysanoéssa neglecta and has united these into a single species with 
two varieties.t ‘ 
-Zoeas were also observed on various occasions, but their numbers were few, and 
no attempts were made to determine the species represented by them. 
PROTOCHORDATA. 
Tunicate larve and Appendicularians were observed, the former in considerable’ 
numbers, on November 11, and in the early part of January, the latter only rarely in 
October. The Appendicularians were not in a satisfactory condition for exact deter- 
mination, but apparently both Fritillaria and Oikoplewra were represented. 
PISCES. 
A few pelagic fish eggs were taken on two occasions, April 21 and May 13, but 
it was not possible to determine their source, since their preservation had rendered 
them almost opaque. A young fish, about 1 cm. in length was also taken on April 21 
at the 3-fathom level.. It was a young example of Liparis liparis Linn. and had 
evidently been engaged in feeding upon plankton Copepods, one of which was- 
observed within its jaws. 
This fish, with its suctorial disk, is essentially a bottom form, its suctorial disk 
being an adaptation to that mode of life, and its capture in a plankton-net is there- 
fore a matter of some interest. 
Notr.—A further study of the plankton in the neighbourhood of St. Andrews during the 
past summer has revealed errors in the identification of two of the forms mentioned above. 
That which was doubtfully regarded as Rhizosolenia gracillima proves to be Thalassiothrix 
longissima Cleve and Grunow, while the forms identified as Hurytemora hirundoides were pro- 
bably merely immature examples of H. herdmani. This latter correction is based upon obser- 
vations kindly communicated by my friend, Dr. Arthur Willey. 
1See H. J. Hansen. The Crustacea Euphausiacea of the United States National Museum. 
xlviii, 1915. 
