An Account of the Deep-Sea Ophiuroidea collected by the Royal Indian Marine Survey Ship “Investigator”

Abstract

THIS monograph, published by order of the Trustees of the Indian Museum, is well worthy its predecessors, now famous, and adds one more to the brilliant results of the Investigator, memorably associated with the names of Dr. A. Alcock, its editor, now superintendent of the Indian Museum, and his indefatigable co-workers in the Zoology of the Indian Seas. It is chiefly devoted to the description of forty species of Ophiurids which are new, the majority of the larger number obtained during the cruises of the ship having been already reported upon by Prof. Koehler in the Annales des Sciences Naturelles, as explained in the text. The new forms are of the genera Ophiacantha (7 species), Amphiura (5 sp.), Ophioglypha (4 sp.), Ophiomusium, Ophiactis, Ophiochiton, Ophiomitra, and Gorgonocephalus, each 2 sp., and thirteen other genera each 1. Interest chiefly centres in a new genus, Ophiotypa, obtained in the Gulf of Bengal at 1997 fathoms. O. simplex is the name by which the author would have it known, its special structural peculiarity being the great size of the primary plates of the disc, the aboral region of which is beset by an enormous pentagonal centro-dorsal and five equally large radials, separated by small but regular inter-radials. Interbrachial plates are present on the ventral face. Radial shields are absent, and the author, regarding this character and the small number of plates present in the disc of the adult as primitive, proceeds to a comparison with the young stages of Amphiura, as described by Ludwig and Fewkes, which would seem to justify the conclusion that Ophiotypa, as regards its skeleton, may be a persistently embryonic form.

An Account of the Deep-Sea Ophiuroidea collected by the Royal Indian Marine Survey Ship “Investigator.”

By R. Koehler. (Calcutta: 1899.)