200 
SPOLIA ZEYLANICA, 
increase in size being accompanied by periodic exuviation or 
casting of the cuticle. During this critical process the delicate 
feet are apt to be broken off, or an entire limb may be lost. When 
this happens the mutilated member is restored by regeneration, 
and the regenerated appendage always differs from a normal 
limb in some particulars, as for example in regard to the occurrence 
of spines on the femora, &c. (see figure). The most marked dif¬ 
ference concerns the number of joints in the feet (tarsi), which 
are reduced by one less in the rejuvenated legs. Thus the normal 
number of tarsal joints in the Phasmidac is five, the terminal 
joint bearing the claws and the pad, as shown in the case of the 
right middle leg of the figure. The opposed leg on the left side 
has been regenerated, and the tarsal joints are seen to be reduced 
to four. The same thing happens very frequently in the life- 
history of the leaf-insects of the genus Phyllium, which represents 
another modification of the Orthopterous type of organization. # 
(4) Teratodes monticollis. 
The last illustration is that of a remarkable grasshopper, named 
Teratodes monticollis (Gray), taken from the bund of the tank at 
Vavuniya by Mr. William Ferguson last July. This species is 
characteristic of the Northern Province of Ceylon. It was figured 
under the name Gryllus monticollis , Gray, in Griffith’s Animal 
Kingdom, XV., pi. 64, the original locality being given vaguely 
as the East Indies.f It is distinguished by its stout body, short 
wings, short antennae, and especially by the high crest of the 
pronotum, which is produced backwards beyond the insertion of 
the wings. It is placed in the family Pamphagidae (Stal, 1873) of 
the sub-division Acridiodea (Burmeister, 1839). 
This specimen lived for many weeks at the Museum. Its pre¬ 
vailing colour was yellowish, like a fallen leaf, which it strongly 
resembles when at home in the grass. 
Ed., Spol. Zeyl. 
6. Note on Pearl Formation in the Ceylon Pearl Oyster . (By 
Professor W. A. Herdman, D.Sc., F.R.S., and James Hornell.)J— 
Professor Herdman and Mr. Hornell have had two cruises of 
* For further information and discussion on the regeneration of lost parts in 
the Arthropoda, particularly in the Orthoptera, see papers by Mr. H. H. Brindley 
in Proc. Zool. Soc., London. 1897, pp. 903-916, and 1898, pp. 924-958, with full 
bibliography. 
t Of. H. Burmeister, Handbuchder Entomologie, Bd. II., Berlin, 1839, p. 618. 
X Reprinted from the Report of the seventy-third meeting of the British 
Association for the Advancement of Science, held at Southport, September, 1903, 
see p. 695. The “report” is a volume of more than nine hundred pages dealing 
with all branches. It was published in 1904 (London, John Murray). 
