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



basulia, while others of similar structure are bent somewhat outwards above the level of 

 the skin, and others, again, especially in somewhat larger sponges, arc drawn out into 

 true anchors, which exactly resemble the basalia of the adult specimens. 



Genus 3. Rossella, Carter (PL LV., and woodcut, fig. 4). 



1872. Carter, Ann. and Mag. Nat. Hist., vol. ix. p. 409 {Ros^scUa antardira). 



1872. Bowerbank, Op. cit., vol. x. pp. 58-61. 



1872. Gray, Op. cit., vol. x. p. 134 {Rossella philippinensk). 



1873. Carter, Op. cit, vol. xi. p. 275. 



1873. Gray, Op. cit., vol. xi. p. 234 (Pectalia (jlohidosa). 



1873. Wj'ville Thomson, Depths of the Sea (Rossella vclata). 



1873. Carter, Ann. and Mag. Nat. Hist., vol. xii. p. 361. 



1874. Gray, Ojx cit., vol. xiii. p. 284. 



1875. Carter, Op. cit., vol. xv. p. 113. 



1875. Willemoes Suhm, Zeitschr. f. wiss. Zool., vol. xxv. p. 25. 



1876. Marshall, Op. cit., vol. xxvii. p. 113. 



1877. Zittel, Abhandl. d. IL CI. k. haier. Akad. d. ■^^^ss., vol. xiiL 

 1877. Marshall and Meyer, Mittheil. Zool. Mus. Dresden, vol. ii. 261. 



History. — Among some Antarctic sponges which were dredged by Captain Sir James 

 Ross during his voyage of discovery and research in the Southern and Antarctic region 

 in 1839-43 (lat. 74i° S., long. (?), and lat. 77^° S., long. 175' W., from a depth of 

 300 fathoms), Carter found, in 1872, two remarkable and hitherto unobserved forms 

 of siliceous elements — the one a five-rayed spicule in which the longer ray, measuring 

 about 1 cm. in length, ran out to a fine point at one extremity, but passed at the other 

 into four approximately cruciate, straight or slightly bent transverse arms, disposed at 

 right angles; the second, a four-toothed anchor with a long (at least 4 cm.) shaft and 

 cruciately disposed, somewhat strong, recurved teeth, which ran out into simple points. 

 In some anchors the straight shaft was continued to the other side of the anchor teeth, so 

 that with the projecting point the entire structures became hexradiate. 



While all parts of the anchors were smooth, the rays of the five-rayed spicules, which 

 are hkewise round, were thickly beset with very fine microspines ; on the four pointed 

 transverse arms, however, numerous larger slightly bent tubercles also occurred with 

 their free points turned away from the intersection of the arms. Although the sponge 

 bodies to which these spicules belonged were not discovered, it seemed certain that the 

 two kinds of spicules belonged to one and the same sponge, which Carter named Rossella 

 antarctica. This procedure certainly seemed at first somewhat rash, and Bowerbank did 

 not fail to declare his disapproval.^ Further discoveries, however, soon served to justify 

 Carter's opinion. 



In the same year, Gray found a second species of the same genus among the sponges 



' Ann. and Mag. Nat. Hist., ser. 4, vol. x. p. 58. 



