ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 295 



bream. We cannot do more than refer to this interesting study in 

 natural history. 



History of the Whale-Shark.* — Barton A. Bean has an interesting 

 story to tell in recounting the history of Rhmodon f //pirns Smith, the 

 whale-shark.. It was first known in 1828, when it was captured at the 

 Cape of Good Hope, but has since been recorded from the Indian Ocean, 

 the Gulf of California, the Gulf of Panama, the coast of Florida, and 

 Celebes (?). Unlike other sharks, it has a terminal mouth, and the jaws 

 are provided with ribbon-like dental plates of extremely numerous and 

 minute teeth. It is said to grow to a length of 60 ft., so that it is only 

 surpassed in size by the right whale. The Florida specimen was IS ft. 

 long. Like the basking shark of the North, it feeds on minute animals, 

 such as Copepods, other Crustaceans, and Molluscs. It is a slow, apa- 

 thetic fish, harmless to man, and is wont to bask on the surface. 



Eye in Selachians.f— V. Franz has made a detailed study of the 

 structure and functional adaptations of the eye in numerous types of 

 Selachians. The general characteristics are the spherical lens, the 

 epithelial lens muscle, the enlarged posterior and diminished anterior 

 bulbus segment, the predominantly cartilaginous sclerotic, the some- 

 what arched thin and large cornea, the ciliary body, the peculiarly-formed 

 tapetum lucidum, the epithelial iris-musculature, the absence of meso- 

 dermic musculature in iris, ciliary body, and choroid, the peculiar zonula 

 zinnii, the absence of a falciform process and vitreous vessels. 



The author's discussion of optical, hydrostatic, mechanical, and other 

 adaptations, is of much interest. 



Asterolepid Appendages.^ — C. R. Eastman discusses the various 

 interpretations of asterolepid appendages, and points out that the absence 

 of an appendicular skeleton, and the peculiar mode of attachment, offer 

 such striking contrasts to the fins of fishes, as to make it impossible to 

 conceive of a homology existing between them. They may be regarded 

 with much probability as having developed from a muscular flap, or 

 integumentary extension of the body, being of kindred nature with 

 tactile or clasping organs, or with the frontal spines of Chiimeroids. 

 The fact that one of the dermal plates is pierced and otherwise modified 

 for their attachment, would seem to indicate that, pari passu with the 

 development of body-armour, the paired muscular extensions also become 

 encased in plates. Sphinx-like though the problem be, as to how and 

 when these structures originated, the evidence seems tolerably clear th.it 

 they are not derivable from fish fins. 



New Cephalaspid.§ — F. Chapman describes TJvyestes magnificus sp. n., 



a new Cephalaspid from the Silurian of Wombat Creek, Austral ia. It is 

 of great interest, not only on account of its being the oldest recorded 

 vertebrate from Australia, but also because of its large size. The genus 

 Thyestes has hitherto been known from small-sized species, but T. mag- 



* Smithsonian Misc. Collections, xlviii. (1905) pp. 189-48 (3 pis., 2 figs.). 



t Jena Zeitschr., xl. (1905) pp. 697-840 (1 pi. and 32 figs.). 



% Aracr. Journ. Sci., xviii. (1904) pp, 141-4. 



§ Proc. R. Soc. Victoria, xviii. (1900) pp. 93-100 (2 pis.). 



