82 BIOLOGICAL SURVEY OF 



trust that the determinations are correct. Lambe has pub- 

 lished descriptions of the sponges taken at various times 

 from the Gulf of St. Lawrence, coast of Nova Scotia, Davis 

 Strait, and Baffin Bay, and these descriptions have been of 

 great service, as the sponge fauna of the Mt. Desert Island 

 region appears to be almost identical with those regions 

 farther north. The Danish Ingolf Expedition came as far 

 west as Davis Strait and the forms belonging to the three 

 families, Homorrhaphidae, Heterorrhaphidae, and Desmaci- 

 donidae, have been most carefully and painstakingly described 

 by Lundbeck. The Challenger Expedition dredged south of 

 Halifax, Nova Scotia, in 85 fathoms, and the Prince of 

 Monaco's Expedition worked at a depth of 75 fathoms off 

 the coast of Newfoundland. 



All the records of the occurrence of monaxonid sponges 

 which have been taken at 100 fathoms or less have been ex- 

 tracted from these various reports and lists and tabulated. 

 The table includes the records for a region extending from 

 Vineyard Sound to Cape Farvel, the southernmost point of 

 Greenland. Cape Farvel was chosen as the limit of the Ameri- 

 can forms because the 0°C. isotherm comes into the shore at 

 about Cape Farvel and this isotherm is not resumed to the 

 west except in the northern part of Baffin Bay and also be- 

 cause the depth of the water falls off very rapidly to 1000 

 Danish fathoms (= 1060 English fathoms) at this place. The 

 monaxonid sponges taken by the Danish Ingolf Expedition in 

 Davis Strait could not be included in its entirety because 

 only three families have been studied thus far. 



The depth of 100 fathoms was chosen as including, for the 

 most part, the greatest depth found in the Continental Shelf. 

 However, in the Gulf of Maine, Davis Strait, and Gulf of St. 

 Lawrence, there are regions which are deeper than 100 

 fathoms and essentially deep-water forms have been taken 

 from these places. 



The terminology and method of classification used in the 

 following descriptions is the same as that used by Lundbeck, 

 who in turn has largely followed Ridley and Dendy. No 



