1893. CORRESPONDENCE. 319 



sheet. In like manner, the fragments c and d also were found, as I personally know, 

 in different drives far apart from each other. The chances, therefore, of these frag- 

 ments all belonging to the same bird are infinitely little. 



Each may represent a different species, or even a different genus. Mr. Hutton 

 has, however, boldly deduced the length of the tibia of his new species from the one 

 set of fragments, and its metatarsus from the other set. On this compound structure 

 he has built conclusions as to the early forms of Dinornis, and as to the pedigree of 

 others. The author observes, on p. i6, " It will be seen that my inference that the 

 Moa bones from Timaru belonged probably to the genus Anomaloptevyx was a correct 

 one." 



If we now turn to his own diagnosis of the genus (tom. cit , xxiv., p. 123) we find 

 it to be based on certain characters of the skull, sternum, and pelvis — bones which, 

 in the present species, are all unknown ; and on the metatarsus being shorter than 

 the femur (here also undiscovered), and on its length being 20-2-3 times the girth 

 of the shaft, which again is lost in both fragments. Anomaloptevyx is further defined 

 by its tibia being " 2-1 to 22 times the length of the metatarsus, and its breadih 

 between 4-2-5I times the girth." As already pointed out, the tibial fragments are 

 "much hidden in the matrix," and imperfect at both ends, and Mr, Hutton now 

 admits that " the length of the metatarsus is unknown." There is left, therefore, 

 not a single character by which these fragments can be referred to Anomaloptevyx, as 

 defined by him, or to any other genus or species. 



Of the additional species described in this volume as new, nearly all are based 

 on bones exhumed at Enfield, and examined with considerable care by myself. 

 When arranged in a series of several yards in length, the one bone merged into its 

 neighbour so gradually that it was quite impossible to draw any line and say the bones 

 to the right ought to belong to one species, those on the left to another. The bones 

 associated together by Mr. Hutton to form a limb are purely guess-work, and may 

 or may not belong to one species (not to say individual) and the comparative 

 dimensions of its different parts can have only conjectural value. Indeed, most of 

 the separate bones might easily be fitted to different existing species, for it is well- 

 known that the bones of birds of ancient pedigree vary greatly in their dimensions. 

 From descriptions such as are given by Mr. Hutton, unaccompanied by figures, it is 

 impossible to identify the species of Dinoviiis he has established. They merely 

 increase the already almost inextricable confusion which those who are working on 

 this subject are compelled laboiiously and unnecessarily to unravel. 



Henry O. Forbes. 



Latent Congenital Variation in a Lucernarian ? 



It seems to be the fact that the Lucernarians examined by Mr. Hornell, and 

 described in his note in the July number, were abnormal when gathered. On January 6 

 of this year I received from Messrs. Sinel & Hornell two specimens of Haliclvstus 

 octoradiatus, normal as to the number of arms, c-cystophores, and septa. They were 

 put into a tank in good order, and containing a fair supply of food in the shape of 

 small Crustacea. On the 8th, no abnormality was perceived, and illness prevented 

 my visiting the tank for some days; but when next seen, one specimen had eleven 

 tentacular arms instead of eight. The other specimen continued normal till death. 



The per-radial joining c-c^ and c-c* — which were slightly smaller than the 

 others — divided the animal into an upper abnormal and a lower normal half. The 

 latter calls for no observation. Between c-c'' and c-c ^ were two arms well developed ; 

 between c-c'' and c-c^ were also two arms, but that next c-c^ was smaller than its 

 neighbour; there was a single arm between cc'' and c-c*'; and between c-c** and 

 c-ci arm*" was duplicated. 



.As I felt unable to deal with the problem, I offered the animal to Professor 

 E. Ray Lankester, at whose wish it was sent to Mr. Garstang, at Plymouth, who, with 

 regard to the last-mentioned arm, wrote to me thus: — " Arm "^ has now only one 

 bunch of tentacles ; but there is an abrasion on one of its edges, near c-c", and 

 possibly one of the supernumerary arms has sloughed away from that spot." 



