360 DISCOVERY REPORTS 



placed more proximally and directed more frontally than in T. aquilina. The opesia is 

 usually a little shorter than in T. aquilina. 



Emma Gray, 1843 

 1. Emma triangula Hastings. 



Emma triangula Hastings, 1939, p. 323, text-fig. 272 A. 

 Station distribution. New Zealand: Sts. 934, 935. 

 Geographical distribution. Australia ; New Zealand (Hastings). 



Scrupocellaria Van Beneden, 1845 

 1. Scrupocellaria ornithorhyncus Thomson. Fig. 17 B. 

 Scrupocellaria ornithorhyncus Thomson, 1858, p. 144. 

 Scrupocellaria ornithorhynchus Busk, 1884, p. 24, pi. xi, fig. 6; MacGillivray, 18866, p. 102, 



pi. cxxvi, figs. 9, 9 a-c; 18876, p. 200; Livingstone, 1929, p. 53. 

 Scrupocellaria pilosa Busk, 1884, p. 24, pi. xi, fig. 7. 

 Station distribution. Sub- Antarctic : South Atlantic Ocean, Sts. 4, 5, 339, 1321. New Zealand: 

 St. 934. Victoria: St. 1686. 



Geographical distribution. Victoria (Thomson; MacGillivray; Discovery); Tasmania 

 (50. 1 .21 . 19); Sandwich Islands (Busk 1 ); New Zealand (Livingstone; Discovery); Island of South 

 Trinidad, off Brazil (Terra Nova); John Adams Bank, off Brazil (1937. 10. 14. 1); Tristan daCunha 

 (Busk ; Discovery) ; Gough Island ; Magellanic Region (Discovery). 



The Discovery specimens from Tristan agree exactly with those from the same group 

 of islands wrongly determined by Busk (1884, p. 24) as Scrupocellaria pilosa Aud. (see 

 Harmer, 1926, p. 383). The species from Tristan agrees very closely with Australian 

 specimens believed to belong to S. ornithorhyncus Thomson. In both, the distal border 

 of the aperture is tuberculate in fertile zooecia (Fig. 17 B) ; the full complement of spines 

 appears to be four outer and two inner; and some of the marginal avicularia are 

 large, and have a stout, sharp-pointed end to the beak, as figured by both Busk and 

 MacGillivray. MacGillivray described S. ornithorhyncus as having a bifurcate or double 

 spine close to the base of the scutum, but he was probably misled by the very close 

 approximation of the two inner spines. With one exception the spines in his figure 

 accord with this interpretation. 



Busk described the Tristan species as slender, and S. ornithorhyncus as very slender, 

 though his figures (1884, pi. xi, figs. 6 a, 7 a) depict S. ornithorhyncus as the stouter of the 

 two. In reality there is no appreciable difference in this respect between his specimens. 

 There is some variation in the stoutness of the branches in the British Museum material 

 as a whole, but this appears not to be correlated with distribution. Thomson described 

 the cryptocyst of S. ornithorhyncus as granular (" tuberculated crescentic plate"), but 

 Busk described both forms as having smooth cryptocysts. In reality both are variable; 

 a few distinct granulations are sometimes to be seen in specimens from Tristan, and 

 in Australian material zooecia with quite smooth cryptocysts can be found. 



1 A specimen in the Busk Collection, collected by the 'Challenger' at the Sandwich Islands, and labelled 

 S. ornithorhynchus, proved to be wrongly identified (see Harmer, 1926, p. 370), but true S. ornithorhyncus 

 was also obtained from that locality by the ' Challenger' (87 . 12 .9. 10S). 



