198 



too narrow in the figure, as the specimen has apparently contracted some- 

 what on preservation (it is sUghtly distorted, which has been corrected in 

 the figure). The posterior end is rather elongated, with a somewhat in- 

 distinct, round body at one side, and some accumulated cells which prob- 

 ably indicate the presence in the fully formed larva of some kind of cal- 

 careous bodies. It has a faint greenish colour. — Beyond this stage I did 

 not succeed in rearing the larvse, and no more specimens containing ripe 

 sexual products were obtained, the breeding season of the species being 

 evidently passed by the beginning of November. 



Auricularia nudibranchiata Chun. 



Since Chun observed this magnificent larva at Orotava in March 1887 

 it has never been recorded again from the Atlantic. I was therefore very 

 pleased in finding a specimen during my stay at Tobago, B. W. I., in April 

 1916, proving thus its occurrence also in the West Indian seas. It has further 

 been found in plankton samples from the following locahties in the Sar- 

 gasso Sea and in the vicinity of the Azores: 45° 32' N. 25° 50' W., 24/VI, 

 1911 (1 specimen); 40°47' N. 21°10' W. 21/III. 1911 (1 specimen); 39°22' 

 N. 22° 49' W. 20/III. 1911 (2 specimens); 36°13' N. 33° 50' W. 15/III. 1911 

 (1 specimen); 34° 39' N. 40° 54' W. 13/III. 1911 (several specimens); 33°55' 

 N. 43° 40' W. 12/III. 1911 (several specimens); 30° 30' N. 49° 57' W. 22/11. 

 1911 (2 specimens). This shows that it is fairly widely distributed over 

 the ocean, the time of its occurrence extending at least from February to 

 June. None of the specimens exceed the largest specimens found by Chun 

 in length (6 mm), and none of them are in a further stage of development 

 than the more advanced of Chun's specimens. 



While the species had not been rediscovered in the Atlantic till now, it 

 was recorded in 1911 by H. Ohshima^) as occurring in the seas of Japan 

 (the Sagami Sea), and quite recently MacBride^) has recorded it from 

 off the North end of New Zealand. It is, of course, beyond doubt that 

 these larvse from the Japanese and New Zealand seas really belong to the 

 type of A. nudibranchiata; but it is equally certain that they are not the 

 same species as the Atlantic form. In accordance with the nomenclature 

 here adopted I shall designate the three forms respectively as species a, 

 b and c, the Atlantic form being, of course, designated as species a. 



1) Hiroshi Ohshinia. Note on a gigantic form of Auricularia allied to A. nudibranchiata 

 Chun. Annot. Zool. Japon. VII. 1911. p. 347. 



2) E. W. MacBride. Echinoderma (Part II) and Enteropneusta. Larvse of Echinoderma 

 and Enteropneusta. British Antarctic ("Terra Nova") Expedition. 1910. Zoology. Vol. IV. 

 p. 88. 



