rWADIW /7N// /:/.'//> I.XI'EDITIOW IDlfi-lo 187 



5. Clausocalanus arcuiconiis. — Previously recorded by Wheeler from the Gulf 

 Stream. In the deep surface tow of Acadia station 74 there were very few copepods ; 

 out of a total of 25 counted, il were of this species, the others being C. finmarchicus 

 III (5), IV (3), 9 (1); C. minor (2); Scolecifhri.r minor (1), dance (1); Acartia 

 sp. (1). 



6. Pseudocalanus elongatus. — The abundance of this small but rich and oily species 

 in the gulf of St. Lawrence is paralled by its frequency in the gulf of Maine. In the 

 intervening stretch of water between the entrance to Cabot strait and to the bay of 

 Fundy it does not occur in such great numbers. In the May plankton of the gulf of 

 St. Lawrence between Prince Edward island and the Magdalen islands, it constituted 

 on the average between eighty and ninety per cent of the copepod content. At several 

 other stations inside the gulf if reached to 20 per cent and upwards. In none of the 

 Acadia stations outside the gulf did it attain as much as 20 per cent, the nearest to 

 this quantity being 17 per cent at station 67; 15 per cent at SO and 90; 14 per cent at 

 36.- In all the females which have come under my observation in the preserved material 

 the ovisac was ruptured and the eggs appeared to be attached singly to the genital 

 segment, sometimes one at a time, frequently two, rarely three. Often the shreds of 

 the stalks of attachment are left behind after the egg has been liberated or torn away. 

 When two eggs are present they may be seen to be attached separately side by side. 

 Sometimes there will be one egg and the shrivelled stalk of another beside it. Sperma- 

 tophores are sometimes applied to one and the same female in great numbers. In the 

 example represented in fig. 6, I counted as many as twenty-four spermatophores. 



Fig. 6. — Pscudocidnnu^ elomiatux 9, beset with spermatophores, ''Princess" 

 station 30, August 4th. 30-0 metres. 



7. yEtideus armatus and Gaidius tenuispinus. — Neither of these species has been 

 recorded previously from eastern American waters, that is to say not by Wheeler nor 

 by Bigelow. They occurred together in Acadia station 75 in the vertical haul (180-0 

 fathoms or 325-0 metres) and again at station 87 (290-0 metres). Another noteworthy 

 record for Gaidius was at No. S3 station 23 in the closing net from 340-145 metres. 

 Besides this it was present in the vertical haul at Acadia station 46 (270-0 metres). 



^tideus was not found at any station in the gulf of St. Lawrence. In addition 

 to the two Acadia stations mentioned above it occured also at stations 17 (200-0 m) ; 

 25 (120-0 m.) ; 44 (270-0 m.) ; 74 (325-0 m.) ; 79 (325-0 m.) ; 85 (270-0 m.) ; 8G 

 (290-0 m.). 



8. Undeucha'ta major and minor. — These were not found by Wheeler but they are 

 mentioned by Bigelow (1915, p. 287). They are Gulf Stream species and minor is the 

 more frequent. They occurred together at Acadia sta^tions 46, 74, and 76. The.y are 

 found also in the San Diego region whence the male of U. m,ajor has been described 

 by C. O. Esterly (1905). The male of U. minor has remained hitherto unknown. 

 Several examples were taken in the Acadia hauls. The structure of the fifth feet of 



6551— 16J 



