﻿CRlSTACIvX MAI.ACOSTRACA 11. 



tai/ais G. O. vS. with i6 species, I.rf>togiiathia G. O. .S. witli 14 species, Pscndotaiiais G. O. S. witli 

 5 species, Cryptocopi- G. O. S. with 4 species, //tiploropc G. (). S. with 2 species. Strongylura (j. O. S.. 

 Anarlkriira G. O. S., AIcso/aiKiis DoUf., Pcnuolus Ricliardsoii. Tdiiuissits Stebb., Ttuuiella Norm. (S: vStelib. 

 and Batliyfnnais Beddard, each with a single species. In all i.S genera with 107 species. 

 Thus the order Tanaidacea comprises 26 genera with about 149 species. 



Results and Questions. 



A. The "Ingolf" Collection. 



According to the literature only 9 species lia\'e hitherto been known from the coasts of (Green- 

 land and the adjacent deep-sea area; the number (if deep-sea species secured North of Lat. 56" N. b\- 

 the English expeditions was small, and the excellent collector of small Crustacea Prof. G. O. Sars 

 captured onlv 8 species of Tanaidacea during the Norwegian North-Atlantic Expedition. Judging 

 from these and other facts every zoologist would have thought it to be a good result if the "Ingolf'' 

 had raised the number of species known from the seas around our northern dependencies to twenty 

 or possibly twenty-five. I->ut as already stated, the "Ingolf captured 71 species of Tanaidacea, some 

 other expeditions or travellers added 6 species, and a single deep-sea species enumerated in the 

 literature as taken liy the -Valorous" within the area in question was not found again. — Besides it 

 may be stated, that a good number of the new species were taken by the "Ingolf" at several stations 

 and sometimes in considerable numbers. 



Of the 78 species only 8 belong to the Apseudid^, but 70 to the Tanaida>. The animals 

 belonging to the Apseudidte are on the whole con.siderably or much larger than the Tanaidie and 

 consequently far less overlooked by collectors. But as oul\' N species — 3 among them new — of 

 Ap.sendidai were secured h\ the "Ingolf" and the -Thor", while 42 species are described in the literature 

 from all seas together, the number of species from our northern area is not even one-fifth of species 

 hitherto established. As to the Tanaidie the result is ver\- different; 106 species were known from 

 all sea.s, but the "Ingolf', etc. captured 70 species, thus almost two-thirds as inan\- as hitherto known. 

 And 49 species of the Tanaidte are new to science. 



These excellent results are mainl\- due to a method of collecting introduced b\' me during 

 the first "Ingolf" cruise. A considerable quantity of the mud hauled uj) by dredge or trawl, or the 

 whole bottom material when its quantity was less considerable, was sifted under water in smaller 

 portions in a sieve clothed with silk gauze no. 7 used b\- millers; the well-sifted contents of the sieve 

 were put in alcohol and later examined at home in small portions, in w ater or alcohol, on the lower part 

 of a cheese-cover under a moderately magnifying lens. In this wa\ hundreds of small animals, as 

 Tanaidacea. .-Vsellota, etc.. were gathered. Other deep-sea exjieditions could certainly have arrived at 

 corresponding results if their methods of dealing with the bottom material had been more satisfactory; 

 it may be considered cpiite certain that hundreds of species of small Crustacea etc. lived in the i)ottom 

 materials hauled up b\- the "Challenger" and later great l<;uro])ean and North .\mericau expeditious 

 and were flushed into the sea again. 



