358 DISCOVERY REPORTS 



and are less tapering proximally and less sinuous in outline than those of colonies 

 with shorter fertile internodes. Most of the zooecia have no frontal avicularia, and the 

 lateral avicularia, which are not present on all the zooecia, have their palatal surface 

 tilted obliquely towards the frontal surface of the colony. The scutum is usually un- 

 branched and not much curved over the opesia, commonly having the appearance of an 

 extra spine rather than a typical scutum. Other specimens are, however, more or less 

 intermediate between T. fuegensis (Busk) and T. fuegensis (Jull.). For example, some 

 fragments from St. WS 85, with as many as nine zooecia in a fertile internode, have 

 slender zooecia, branched scuta, lateral avicularia not tilted and often absent, frontal 

 avicularia commonly present; and in Kluge's figure of a specimen from Kerguelen 

 (described as Scrapocellaria bifurcata), also with nine zooecia in the fertile internode, 

 some of the avicularia appear to have the oblique palatal surface, and the non-fertile 

 internode is straight and fairly stout, but frontal avicularia are present, and the scuta 

 are well developed and curved over the opesia. 



Kluge regarded his S. bifurcata as differing from Tricellaria aculeata (Busk) chiefly 

 in the presence of a marginal avicularium, which he recognized as a variable character, 

 and in the presence of four distal spines on most zooecia, but some specimens from the 

 Falkland Islands may have four spines on most of the zooecia (Vallentin Coll. 35.3.6. 298 

 and 377), and the majority of South American specimens have four on some zooecia. 

 Material from Kerguelen in the British Museum shows similar variation ; that of Busk 

 1879 nas f° ur s P m es on some zooecia and four are commonly present on the zooecia of 

 specimens found among unnamed material from Challenger St. 149 (34. 11 . 12.78). 

 Hasenbank's specimens from Bouvet Island are described with four to six spines. All this 

 strongly supports Harmer's conclusion that Scrupocellaria bifurcata Kluge is a synonym 

 of Tricellaria aculeata. 



Considering the irregularity of the distribution of avicularia and scuta and the varia- 

 bility in their size, the less powerful optical instruments of a century ago, and the fact 

 that d'Orbigny's specimens come from the same region as those since described, a region 

 from which no specimens agreeing more exactly with his figures are known, I agree 

 with Harmer and Marcus that one should accept d'Orbigny's name for this species. 



All the material from New Zealand that I have examined has short rather strongly 

 calcified zooecia with usually four or five spines on the distal zooecium of the internode. 



Canu and Bassler (1929, p. 224) put this species into a new genus Monartron with 

 Menipea [Emma] cyathus Thomson as genotype. M. cyathus differs from the other species 

 of Emma, as understood by Harmer (1923), in its hyperstomial ovicell, slight cryptocyst 

 and uniserial joints, and one can quite well argue that it should be separated from 

 Emma, but, except for the one character of the uniserial joints, Tricellaria aculeata 

 resembles T. ternata (genotype of Tricellaria) more closely than it does Menipea cyathus. 

 Whatever views one may hold about the position of M. cyathus there is clearly no 

 justification for separating Tricellaria aculeata from T. ternata in order to associate it 

 with Menipea cyathus. 



Busk's figure (18526, pi. xxiii, fig. 1), supposed to represent the ancestrula and first 

 few zooecia of M. patagonica, agrees so closely with the type-specimen of Tricellaria 



