46 THE VOYAGE OF H.M.S. CHALLENGER. 



The specimens from localities (2) and (3) are a little doubtful, as they are not in 

 good condition. The following specimen, which is in still worse condition, and cannot 

 be identified, may possibly belong to the present species : — 



(5.) June 3, 1874; Station 163b, off Port Jackson, Australia; lat. 33° 51' 15" S., 

 long. 151° 22' 15" E. ; surface ; surf. temp. 69°; one small specimen (? ?), 3 mm. long 

 (in bad condition). 



Doliolum ehrenhergi, Krohn. 



Doliolum chrenbergii (also Doliulum denticulaium), Krohn, Arch. f. Natiirgesch., Jahrg. IS, Bd. i. 



p. 57, 1852. 

 Doliolum denticulaium, Q. and G., Keferstein and Ehlers, Zoologische Beitriige, 1861. 

 Doliolum ehrenbergii, K., Ussow, Proc. Imper. Soc. of Nat. Hist., &c., vol. xviii. fasc. 2, Moscow, 1876. 

 Doliolum deniiculatum, Q. and G., Grobben, Arb. zool. Inst. Wien, Bd. iv. 1882. 

 Doliolum ehrenbergii, K., Uljanin, Fauna w. Flora d. Golfes v. Neapel, 1884. 



This common species was first found and described in 1852 by Krohn, who, 

 however, was under the impression that he was dealing with Quoy and Gaimard's 

 Doliohiia denticulatum. About ten years later it was more fully described by 

 Keferstein and Ehlers. Since then the species has been discussed by Ussow, Grobben, 

 and Uljanin. 



This species difters from the last (comparing Uljanin's account ol Doliolum ehren- 

 hergi with Huxley's of Doliolum denticulatum) in the branchial sac, which in the 

 present species has a larger numl)er of stigmata (up to forty-five on each side), and 

 extends forward ventrally to the first muscle band (PL III. fig. 5).^ The endostyle is 

 short. It commences one-third of the way from the second to the third muscle band, 

 and only extends to the fourth, so that it does not cover two intermuscular spaces (see 

 PI. III. fig. 5). 



I place in this species, with a certain amount of doubt, the following specimens 

 collected during the Cliallenger Expedition : — 



(1.) June 17, 1874 ; Station 165, South Pacific, between Au.stralia and New Zealand ; 

 lat. 34° 50' 0" S., long. 155° 28' 0" E. ; surf temp. 64°-5 ; one small specimen. 



(2.) February 11, 1876; Station 318, South Atlantic; lat. 42° 32' 0" S., long. 56° 

 29' 0" W. ; tow-net at trawl down to a depth of 2040 fathoms ; bottom temp. 33°-7, 

 surf. temp. 57°"5 ; eight specimens, in rather bad condition. 



(3.) Same place ; tow-net at surface ; two specimens. 



(4.) April 29, 1876 ; North Atlantic, off the West Coast of Africa, lat. 18° 8' 0" N., 

 long. 30° 5' 0" W., at night ; surf, temp., at midnight, 73°"7; a dozen specimens. These 

 last have the stigmata extending forwards to between the first and second muscle bands, 



(5.) May 12, 187G ; North Atlantic, lat. 42° 54' 0" N., long. 28° 54' 0" W. ; surf, 

 temp. 58°'2 ; one specimen. 



1 It must be pointed out, however, that Kefersteia and Ehlers represent their so-called Doliolum denticulatum, 

 which Uljanin identifies with the present species, as having the stigmata extending ventrally only as far forwards as 

 the third muscle band. 



