64 



DE. G. H. FOWLER — BISCATAX PLANKTON 



enough to inform me that they are siiecificaliy identical, even when tested by his new 

 criterion of the character of the tips of the jaws. 



No species, to my knowledge, alters more from damage in the to\v-net and from faulty 

 preservation than this. In transparent and well-preserved specimens (fig. 7) the lateral 

 fields may shrink inwards so as nearly to carry the anterior fins out of sight ; such 

 specimens are slightly flattened latei-ally. But in specimens caught early in the haul, 

 which were crushed hy pressure of the water against the net and were dead before 

 preservation, notably in such specimens when preserved with picric acid, the trunk, or 

 the tail, or more often the whole body, has a corrugated appearance, and the epidermis 

 stands out laterally in a broad selvage, due partly to mechanical dorso-ventral com- 

 pression, partly, I think, to an actual loosening of the epidermis from the subjacent 

 tissue. Tliis compression often makes the lateral fins appear much Avider than they 

 really are, and sometimes even produces such a bridge between the anterior and posterior 

 fins as is attributed to Krohn's species lifm * (fig. 9). 



The lateral shrinkage or dorso-ventral compression made the identification so trouble- 

 some that, for the benefit of future workers, I have drawn fou.r states of f areata, of 

 which I take fig. 8 to be the normal. 



Distribution. — The general table of Chsetognaths and the figures immediately to be 

 given clearly indicate that this is an epiplanktonic species. The following table is an 

 analysis f of the captures with open nets : — 



At 



25 



50 



75 



100 



LoO 



20O 



2m 



300 



350 



O 



37 



16 



84 



100 



100 



1 



2 

 2 



1 I 



1 J 



1- 





1-8 

 0-3 

 7-8 

 lG-8 

 26-9 

 30 

 1-5 

 2-0 

 1-5 

 45 



a 



It occurred also in the closing-nets : — 



150-50 fathoms, average specimens 13'0 ; 

 200-100 fathoms, average specimens 1-4; 



but was not captured below the last zone %. From the above facts it is fairly apparent 

 that the species is distributed from the surface to 100 fathoms, w ith a maximum distri- 

 bution between 75 and 100 fathoms, a feAv specimens living between 200 and 100 fathoms. 



* It is quite possible that the- name hjra was given to some other sijecies compressed in this fashion : if one 

 may iud^e from the general description and from the number of teeth and jaws, Krohn very likely had furcata 

 before him. 



t See Bote, p. 60. 



+ Unless the specimens mentioned under iii. (p. 7-t) are really furcata. 



