476 Miscellaneous. 
(nos. R. 506-508) agree so closely in general characters with the 
genus Bothriceps, Huxley, presumably from the Hawkesbury Beds of 
Australia, that they may be regarded as indicating a new species of 
that genus, for which I propose the name Bothriccps Hualeyt. 
The skull of this species is distinguished from that of the typical 
B. australis by its smaller size and narrower contour, the extreme 
Jength being about 2? inches in the specimen which I take as the 
type (no. R. 507). ‘The sculpture is of the pitted nature charac- 
teristic of the typical species of Bothriceps, which at once serves to 
distinguish this form from Petrophryne, Owen, which (as Prof. von 
Zittel has pointed out) appears to be inseparable from Micropholis, 
Huxley. 
The occurrence of Bothriceps in the Australian Hawkesbury Beds 
and the Karoo System of the Cape district is paralleled by that of 
the Ganoid genus Clithrolepis, which Mr. Smith Woodward has 
recently recorded from the latter deposits. 
On the Phosphorescent Infection of the Talitri and other Crustaceans. 
By M. A. Grarp. 
Several naturalists have noted the phenomenon of phosphorescence 
in Amphipoda of different groups and often badly determined (Gam- 
marus, Talitrus, Orchestia, &c.). Tilesius, Viviani, Suriray, and 
Snellen van Vollenhoven have cited cases of this kind, and the Rev. 
T. Stebbing, in the admirable bibliography of his Report upon the 
‘ Challenger ’ Amphipoda, has summarized these older observations. 
In most cases the observed phosphorescence did not belong to the 
animal itself. In Valitrus, especially, M. de Quatrefages has indi- 
eated the cause of this apparent phosphorescence; it is due to 
Noctilucee which attach themselves to the carapace of the Amphipod 
as they lie upon the damp sand after the retreat of the tide*. 
Therefore my surprise was great when, on the 3rd September last, 
I found on the beach at Wimereux -a phosphorescent Talitrus of 
such intense and continuous lustre that the Noctiluce evidently had 
no part in the phenomenon. It was at 10 o’clock at night, and 
notwithstanding the brightness of the moon, then nearly at the 
full, the luminous TYalitrus could be perceived at a distance of 
several metres. The light was greenish; it proceeded from the 
interior of the body of the Crustacean, which was completely illu- 
minated to the extremities of the antenne and legs, and presented 
no dark points except the two eyes, which formed two black spots 
upon this brilliant ground. The animal walked slowly upon the 
sand, instead of leaping briskly like its congeners. All search made 
on the same night and following evenings to find other Zalhtri in 
the same state were absolutely unsuccessful. 
This excessive rarity of the phosphorescent Yaliéri upon a beach 
on which those animals exist in thousands led me to suppose that 
we had to do here with a parasitic action rather than a physio- 
logical peculiarity. Therefore the next day I examined under the 
microscope a leg cut off from the luminous animal. This limb 
proved to be stuffed with Bacteria swarming among the muscles, 
and particularly visible in the terminal joints, which were thinner 
and more transparent. Under the influence of this microbe the 
* “Sur la phosphorescence de quelques Invertébrés marins,” in Ann. 
Sci. Nat. sér. 3, vol. xiv. p. 236, 1850 (see also ‘ Silliman’s Journal,’ vols. xv. 
and xvi., and ‘ Annals,’ ser, 2, vol. xii. pp. 15 and 180, 1858). 
