BIGELOW: COAST WATER EXPLORATION OF 1913. 339 
than in oceanic water (Farran, 1910). And though Temora longicornis 
and Euchaeta norvegica are rather more northern, neither of them is 
distinctively polar. The only members of the copepod fauna which 
ean be classed in that category, Calanus hyperboreus, and Metridia 
longa, are rare in the Gulf. The two oceanic copepods which are promi- 
nent in the Gulf belong, one, Anomalocera pattersoni, to the temperate 
Atlantic, the other, Metridia lucens, to rather more northern waters 
(Cleve, 1900); Pleuromamma and Euchirella alone are clearly of Gulf 
Stream origin, so far as the Gulf of Maine is concerned. 
Only six species of euphausiid schizopods have yet been detected 
in the plankton of the Gulf (1914b, p. 410). One of these, Meganycti- 
phanes norvegica, is very widely distributed in the North Atlantic, 
but much more abundant in boreal water than in polar or warm waters; 
two, Thysanoessa inernis, and raschi are typical Arctic-boreal forms, 
one, Thysanoessa longicaudata, israther more northern, but not polar, 
being found as far south as the southern part of the North Sea, and 
one, Nematoscelis megalops is oceanic, of very wide distribution in the 
North Atlantic. (For the general distribution of these species, see 
Kramp, 1913b). To one species only, Thysanoessa gregaria can a 
southern or Gulf Stream origin be assigned (Zimmer, 1909, p. 21), 
and this one has seldom been taken in the Gulf. 
The only hyperiid amphipods which attain any faunal importance 
in the Gulf, Euthemisto compressa and E. bispinosa, are typical Arctic- 
boreal species, neither of them being found south of the English 
Channel in European waters. Of the two, bispinosa is decidedly the 
more northern (Tesch, 1911) which is suggestive in connection with 
the incursion of this species into the Gulf during the autumn of 1912 
tp. 335). 
The only pteropod which is common in the Gulf, Limacina balea, 
is one of the most typical of boreal organisms, at home neither in pure 
| polar water, nor in the warmer parts of the Atlantic (Meisenheimer, 
| 1906, Paulsen, 1910). Clione limacina is rather more northern, espe- 
| cially abundant on the Grand Banks of Newfoundland, though not 
| an index of polar water (Murray and Hjort, 1912, p. 108). 
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: 
The only chaetognath which is uniformly abundant over the Gulf 
as a whole, Sagitta elegans, has its centre of distribution in boreal 
| coastal waters, though its extreme range includes the Mediterranean 
on the one hand, and the Arctic Ocean on the other (Apstein, 1911; 
| Ritter-Zahony, 1911). The two other species which were taken in the 
Gulf in 1913 are of diametrically opposite origins: — Sagitta serrato- 
jdentata is a southern species; Eukrohnia hamata is Arctic or from 
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