354 ME. HENET B. BIGELOW — BISCATAN PLANKTON : 



The eudoxid of D. appendiculata was taken 



At fathoms in 68 per cent, of the total number of comparable hauls. 



25 — „ 16 „ „ „ „ 



50 — ,. 23 „ „ ,, „ 



75—0 „ 20 



100—0 „ 14 



and in one haul only at all depths below 100 fathoms. 



The eudoxid, then, as already noted, is evidently most abundant at or near the surface, 

 and there is nothing to show that the captures in open nets hauled from 25, 50, 75, or 100 

 fathoms did not come from near the surface, while the net was on its way upward *. 

 The sporadic occurrence of this form at 400-500 fathoms (one closing-net, five specimens) 

 was unexpected. The material is in excellent condition, with well-developed sexual 

 products, and the fact that it was taken in the same haul with three excellent specimens 

 of the polygastric generation suggests that the species was not only alive, but repro- 

 ducing itself at that depth. 



In general, the table of captures shows a great poverty of Siphonophores at the surface 

 in the region studied, the only records from that zone being Diphyes appendiculata and 

 its eudoxid, four specimens of D.fowleri, and a E-hizophysid fragment. 



The greatest abundance of Iluggi/ea kocliii, Diphyes suhtilis, 1). appendiculata (Poly- 

 gastric), and D.foicleri was evidently between 100 fathoms and 25 fathoms. Though 

 Hosacea plicata was taken only below 200 fathoms, it has previously been recorded from 

 the surface, and I have studied specimens from the Pacific taken at the surface. 

 Clmniphyes multidentata, on the other hand, has so far been recorded only from con- 

 siderable depths (p. 349), and is in all probability a typical representative of the 

 permanent Mesoplankton or Intermediate fauna. 



* [I have dealtwith this point elsewhere. In cases where the matter can be checked statistically, it is apparent 

 that, down to something like 100 fathoms, the contamination of the sample obtained by hauling horizontally at 

 (say) 50 fathoms for half an hour through something like half a mile of water, by the fauna of the comparatively 

 insignificant distance of the vertical haul to the surface, is negligible. — G. H. F.] 



