minerals, many Radiolaria-shaped;" at Station 302 there was sediment "consisting almost entirely of small rounded red mineral particles; many of these had the form of both Foraminifera and Radiolaria; and it seemed as if some substance had been deposited in and on these organisms." Similar transitions from well-preserved Radiolarian shells into amorphous mineral particles I have found in several other specimens of Challenger soundings, and consider them a further argument for the supposition that the Radiolaria often take an important share in the formation of the red clay. 240. _List of Stations at which Radiolaria were observed on the Challenger Expedition._--The 168 Stations recorded below, in soundings or surface preparations from which I found Radiolaria, belong to the most various parts of the sea which the Challenger traversed during her voyage round the world; they constitute about half of the (364) observing Stations contained in the official list published in the Narrative of the Cruise (Narr. Chall. Exp., vol. i. part ii. Appendix ii.). In addition to the particulars given in the list regarding the geographical position of the Station, depth, temperature, and composition of the bottom deposit, I have added the result of my investigations as regards the relative abundance of the Radiolaria in each. The five letters (A to E) denote the following degrees of frequency:--A, abundant Radiolaria (AI, pure Radiolarian ooze; AII, mixed Radiolarian ooze); B, very numerous Radiolaria (but not a predominating quantity); C, many Radiolaria (medium quantity); D, few Radiolaria; E, very few Radiolaria (as they occur almost always). In using these symbols regard has been had to abundance of the abyssal as well as of the zonarial and pelagic forms (§ 232); sometimes also the estimated number of Radiolaria has been inserted, based upon information given by John Murray in his Preliminary Report (L. N. 27), and in the Narrative of the Cruise (L. N. 53), as well as by Henry B. Brady in his Report on the {clx}Foraminifera (Zool. Chall. Exp., part xxii., 1884). From Stations 348 to 352 in the Eastern Tropical Atlantic no specimens of the bottom were obtained, but a rich pelagic Radiolarian fauna was demonstrated by numerous preparations from the surface. The depths are given in fathoms and the temperature in degrees Fahrenheit. In the column describing the nature of the bottom the following abbreviations are used:-- rad. oz. = Radiolarian ooze (§ 237). gl. oz. = Globigerina ooze (§ 238). r. cl. = red clay (§ 239). pt. oz. = Pteropod ooze (see p. clviii). di. oz. = Diatom ooze (see p. clvii). bl. m. = blue mud, } terrigenous deposits gr. m. = green mud, } (see p. clvi). volc. m. = volcanic mud, } r. m. = red mud.