THE SIPHONOPHOEA. 353 



a hopelessly tattered state. It was therefore impossihle satisfactorily to sort out, from 

 the material captured, anything like the total number of specimens present. Conse- 

 quently the number of specimens from any haul, sent to Mr. Bigelow, can only be 

 taken to indicate the comparative abundance or scarcity of a species in the very roughest 

 and most general way. Some deductions as to their distribution may, nevertheless, 

 fairly be drawn from the number of hauls in which they occurred. Por reasons given 

 in earlier papers of this series, we must omit, as unfair for comparison with ordinary nets, 

 the nine hauls made at the surface with silk of 180 meshes per linear inch ; there remain 

 16 hauls at this horizon for comparison ; for other reasons 35 c (75 fathoms) and 35 d 

 (100 fathoms) are also omitted. Otherwise the numbers of hauls shown on the general 

 table (p. 358) remain good, since there seems no reason to omit the hauls with a silk at 

 18 meshes per inch, in the case of these comparatively large forms. — G. H. F.) 



The only species taken with sufficient regularity to allow its vertical distribution to be 

 worked out in any detail is Diphyes appendimilata and its eudoxid. 



The polygastric stage occurred between the surface and 200 fathoms 



At fathoms in 18 per cent, of the total number of comparable hauls. 



zo u ,, zo ,, ,, ,, ,, 



50 — „ 38 „ „ ,, ,, 



75 „ 50 5, ,, ,, J, 



100-0 „ 42 



Between 200 and 100 fathoms in 57 per cent, of the total number of comparable hauls. 



Below 200 fathoms it was taken in the only closing trawl made between 500 and 250, 

 and in one each of the three closing-nets hauled from 300 to 200 and from 500 to 400 

 fathoms. It did not occur in any open net from a depth greater than 100 

 fathoms. 



This table shows very clearly that D. appendiculata was not common on the surface, 

 and the preceding one, actual numbers of specimens sorted out, emphasizes this fact 

 even more strongly. On the other hand, it is obviously very rare below 200 fathoms, 

 its only record from below that depth being in the three closing-nets, between 200 and 

 500 fathoms. The tables suggest that it was most abundant between 75 and 100 

 fathoms. It is true that the largest number of captures in proportion to hauls is from 

 200-100 fathoms ; but since the total number of hauls at that zone was only seven, and 

 the total number of specimens small, it is not so safe to draw inferences from them as 

 from the 100-fathom hauls, of which there were over three times as many. But the 

 excellent condition of the specimens taken at 200-100 fathoms shows that they were 

 actually living at that depth. 



That the polygastric stage of D. appcndictdata occurred in none of the eight open-net 

 hauls from below 100 fathoms is rather remarkable, since in their passage upward the 

 nets must, of course, have passed through the zone where tlie species was most plentiful. 

 As pointed out above (p. 345) the sporadic occurrence of this form in the closing- 

 net at considerable depth is not surprising in view of the previous records of its 

 capture. 



SECOND SERIES. — ZOOLOGY, VOL. X. 56 



