BIGELOW: EXPLORATIONS IN THE GULF OF MAINE. 103 
23 we found a single specimen of the medusa Tiaropsis diademata, 
which is abundant in Massachusetts Bay in June. 
At Station 23 we first met Pleurobrachia pileus, and we frequently 
took it later, further north and east; we saw Beroe cucumis on the 
surface, and captured sticklebacks, and a large isopod (Idotea) from 
floating Fucus. In these off-shore waters Sagitta serratodentata was 
more plentiful than we had found it before,— a case treated at length 
elsewhere (p. 121) and an occasional fragmentary agalmid was likewise 
taken (p. 121) besides considerable numbers of fish fry. 
At Station 27 Calanus finmarchicus was taken in swarms at the 
surface, the only time we found it abundant at that level, in the 
day time, though it often was at night. Euthemisto was plentiful 
at the off-shore Stations 29 and 31, and at the former we took one Tiara 
pileata, and two Aglantha (40-0 fathoms), this being the first time the 
latter was encountered during the cruise. On the other hand, we 
found none of the typical shore forms, e. g., Aurelia, Cyanea, Meli- 
certum; and over the Eastern Basin not even Staurophora, Phialidium, 
Beroe, Bolinopsis, or Pleurobrachia, though the last three, of course, 
are not dependent upon shallow water at any stage in development. 
German Bank proved interesting, for though the surface tempera- 
ture was low (52°, Station 30) and the bulk of the tow consisted of 
Calanus finmarchicus, with a few Euchaeta, Anomalocera, a large 
number of the schizopod Euphausia, the amphipods Hyperia galba 
and Euthemisto, Tomopteris helgolandica, Sagitta elegans, and S. 
serratodentata, forming a typical boreal assemblage, the surface haul 
also yielded two large Salpa fusiformis and two specimens of the 
siphonophore Physophora hydrostatica. During the next day Salpae 
were occasionally seen on the surface; and at Station 31 several were 
taken in the tow, all S. fuszformis (p. 121). But here, as on German 
Bank, the plankton as a whole was the same as we had found over the 
Gulf as a whole, Calanus finmarchicus composing far the chief bulk of 
the haul. This proved to be an interesting station, because the open 
net from fifty-five fathoms brought back several specimens of the cold 
water Chaetognath HKukrohnia hamata, a species found on the surface 
in Arctic and Antarctic regions, but limited to the mesoplankton in 
temperate and tropical latitudes. This same haul also yielded two 
specimens of the large Sagitta lyra; and neither of these species was 
taken again during the voyage. The list of copepods also received an 
addition, Luchirella rostrata. After leaving this station we saw no 
more Salpae. 
Twelve miles off Mt. Desert Rock, August 16, 3 A. M., we made a 
