o, many ports of Peru,
Guayaquil, Panama, Galapagos Islands, and all the collections were up to
this sent to the Zoological Station at Naples to be studied by the
naturalists. By this time the ship left Callao for Honolulu, Manila, Hong
Kong, and, as the Challenger had not crossed the Pacific Ocean in these
directions, we made several soundings and deep-sea thermometrical
measurements from Callao to Honolulu. Soundings are made with a steel wire
(Thompson system) and a sounding-rod invented by J. Palumbo, captain of the
ship. The thermometer employed is a Negretti and Zambra deep-sea
thermometer, improved by Captain Maguaghi (director of the Italian R.N.
Hydrographic Office).

With the thermometer wire has always been sent down a tow-net which opens
and closes automatically, also invented by Captain Palumbo. This tow-net
has brought up some little animals that I think are unknown.

G. CHIERCHIA.

Honolulu July 1.

The shark captured by the Vettor Pisani in the Gulf of Panama is _Rhinodon
typicus_, probably the most gigantic fish in existence. Mr. Swinburne Ward,
formerly commissioner of the Seychelles, has informed me that it attains to
a length of 50 feet or more, which statement was afterward confirmed by
Prof. E.P. Wright. Originally described by Sir A. Smith from a single
specimen which was killed in the neighborhood of Cape Town, this species
proved to be of not uncommon occurrence in the Seychelles Archipelago,
where it is known by the name of "Chagrin." Quite recently Mr. Haly
reported the capture of a specimen on the coast of Ceylon. Like other large
sharks (_Carcharodon rondeletii, Selache maxima_, etc.), Rhinodon has a
wide geographical range, and the fact of its occurrence on the Pacific
coast of America, previously indicated by two sources, appears now to be
fully established. T. Gill in 1865 described a large shark known in the
Gulf of California by the name of "Tiburon ballenas" or whale-shark, as a
distinct genus--_Micristodus punctatus_--which, in my opinion, is the same
fish. And finally, Prof. W. Nation examined in 1878 a specimen captured at
Callao. Of this specimen we possess in the British Museum a portion of the
dental plate. The teeth differ in no respect from those of a Seychelles
Chagrin; they are conical, sharply pointed, recurved, with the base of
attachment swollen. Making no more than due allowance for such variations
in the descriptions by different observers as are unavoidable in acco