90 " THETIS " SCIENTIFIC RESijLl'S. 



examples such agree exactly with the descriptions of the old world 

 species. 



The dorsal spines are doubtfully shorter and stouter than in Z. 

 faber, and the base of the soft portion is slightly less than that of 

 the spinous. The spiny scutes at the base of the soft dorsal and 

 anal fins vary in number from seven to eight. In all our examples 

 the thoracic and abdominal scutes are strongly spinose, none at 

 all reduced to the tuberculate character figured by Richardson. 



As will be seen by a reference to the Stations quoted, Dories 

 were trawled on no less than thirty-three occasions. At Station 

 36 they were the only fishes taken, and at Station 37, twenty-eight 

 large individuals were obtained in one haul of two hours' duration 

 immediately south of Botany Bay and within three miles of the 

 coast. Depth, between the extremes at which we trawled, seemed 

 to have no effect on its numbers, it being equally common either 

 at 16 or 84 fathoms. Indeed, the known habits of the British 

 Dory indicate that it may swim freely at the surface, for when 

 the Pilchards appoach the shore this fish is often taken in con- 

 sideraV)le numbers. The only Pilchard obtained by us was voided 

 by a Dory (Station 26), and the single Mackerel was obtained in 

 the same way (Station 38), while, as has been previously mentioned, 

 many of the Yellow-tails ( Trachurus declivis) secured had been 

 partially digested, doubtless by Doiies. When these latter fish 

 were in the trawl the fact was generally made apparent by numbers 

 of dead examples rising to the surface and floating away (owing 

 to their peculiar conformation) on their sides, many were washed 

 over the ground line and thus lost. 



Cunningham* writes: — "In the aquarium at Pl3'mouth I 

 have noticed that the dory has a peculiar and interesting method 

 of securing its prey. It does not overtake it by superior speed 

 like the mackerel, or lie in wait for it like the angler, but stalks 

 it and approaches it by stealth. It is able to do this in conse- 

 quence of the extreme thinness of its body, and the peculiar 

 movement of its hinder dorsal and ventral fins. The doiy 

 places itself end on towards the fish it desires to devour, and in 

 this jiosition it is evident that it excites no alarm on the part of 

 its prey. The appearance of the dory seen in this way is a mere 

 line in the water, to which no particular significance can be 

 attached. I have not particularly noticed the effect of the 

 ribbons of membrane, which project from the dorsal fin. But I 

 have observed that the movements of the dory are very gradual, 

 except in turning : it alters the position of its })ody by a turn of 

 the tail or side fins, and tlien slowl}' swims forward by vibrating 

 the second dorsal and ventral, a movement which causes very 



Cunningham — Marketable Marine Fishes, 1896, p. 322. 



