- OF ete renner no rare er rere = Owe Oe eer ~— danaadenminatadad oameae dadeunetteeae ioe * 2 Soe 7 ee ae - = swe ReSSerr POS eng ote pp ee Cr adeeneh aie al eat eh eS iat BAST ATL SYS Oe A ae OT ee es one Door A - - bh DS a Ae IE TPT OM et a a Sel SO A iy h @e stsoo TOEO O WMWON UNL LONAANH 1OHM/18lN ie Nae ok Ste ene we arty HSE AEM i 0 : | A —* ‘p my es DEPARTMENT OF TERRESTRIAL MAGNETISM J. A. Fleming, Director Scientific Results of Cruise VII of the CarneGie during 1928-1929 under the Command of Captain J. P. Ault BIOLOGY -—I The Copepods of the Plankton Gathered During the Last Cruise of the CARNEGIE CHARLES B. WILSON CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 536 WASHINGTON, D. C. 1942 DEPARTMENT OF TERRESTRIAL MAGNETISM J. A. Fleming, Director Scientific Results of Cruise VII of the Carnecie during 1928-1929 under the Command of Captain J. P. Ault BIOLOGY -—I The Copepods of the Plankton Sormered Wurinc the Mase Ceuise of the CARNEGIE CHARLES B. WILSON CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 536 WASHINGTON, D. C. 1942 iv PREFACE Captain W. J. Peters laid the broad foundation of the work during the early cruises of both vessels, and Captain J. P. Ault, who had had the good fortune to serve under him, continued and developed that which he had so well begun. The original plan of the work was envisioned by L. A. Bauer, the first Director of the Department of Ter- restrial Magnetism, Carnegie Institution of Washington; the development of suitable methods and apparatus was the result of the painstaking efforts of his co-workers at Washington. Truly, as was stated by Captain Ault in an address during the commemorative exercises held on board the Carnegie in San Francisco, August 26, 1929, “The story of individual endeavor and enterprise, of in- vention and accomplishment, cannot be told.” Dr. Charles Branch Wilson, the last of that outstand- ing group of great monographers of the marine copepods which included Brady, Dana, Giesbrecht, Sars, and Thomas and Andrew Scott, died August 18, 1941. Thus the printing of this report on the copepods gathered on cruise VII of the Carnegie could not have his super- vision. We are indebted to Dr. Waldo L. Schmitt, Cura- tor of the Division of Marine Invertebrates of the United States National Museum, and his associates for certain necessary additions to the manuscript, for reading it, and for clearing up a few questions raised in the editorial revisions by the Office of Publications of the Institution and by Mr. C. C. Ennis of the Department of Terrestrial Magnetism. All Dr. Wilson’s records and his very complete library of copepod literature were bequeathed to the Division of Marine Invertebrates, United States National Museum, Washington, D. C. It is hoped that the recipients of this posthumous work of Dr. Wilson’s will continue to con- tribute any publications of their own dealing with cope- pods or marine biology to the Wilson library at the National Museum, in order that it may be kept as up to date as possible. It is fitting to quote here Dr. Schmitt’s appraisal of this memoir in an obituary notice, where, in referring to the three major manuscripts written by Dr. Wilson during the last decade, he says of this one: “It, perhaps the most important in Dr. Wilson’s own opinion, deals with the copepods of the marine plankton taken on the last cruise of the ill-fated nonmagnetic yacht Carnegie. This report, which was submitted for publication several years ago, for the first time in the history of oceanography gives the directly comparable results of simultaneous three-level tows made in all oceans with identical gear, accompanied by full station data, including temperature, salinity, density, phosphates, and hydrogen-ion concentration. In his painstaking tabulation of the species of copepods in every haul and their abundance at each of the three levels investigated, involving the microscopic inspection of many thousands of individual copepods, Dr. Wilson has made available a biologic record of a group of organisms of highest importance in the economy of the seas such as has never been achieved by any marine expedition.” J. A. FLenine Director, Department of Terrestrial Magnetism INTRODUCTION Apparatus AND Metuops Nets Localities Depth of Tow Depth of Tow Supplementary Data Oceanic Currents Comparisons oF PLANKTON Comparison of the Two Oceans .. . Comparison of Different Regions of the Pacific . CONTENTS PAGE I Diversity of Distribution Daytime Stratification Causes of Daytime Stratification Temperature ... crates Salinity (Map 3) and Density Hydrogen-Ion Concentration Phototropism Lists oF SPECIES BY STATIONS Discussion oF Species (Alphabetically Arranged) . LITERATURE CITED List oF Species Discussep Figures 1-136 INDEX 77504 PAGE If It THE COPEPODS OF THE PLANKTON GATHERED DURING THE LAST CRUISE OF THE CARNEGIE INTRODUCTION During cruise VII, 1928-1929, of the nonmagnetic vessel Carnegie extensive collections of plankton were made over parts of the Atlantic Ocean north of the equator and of the Pacific Ocean from 52° north latitude to 40° south latitude. The present paper deals only with the copepods of this plankton, their identification, and their actual and rela- tive distribution. In order to facilitate a correct interpre- tation of the records herewith presented, a preliminary account is given of the apparatus and methods employed. Certain qualifications also, which materially influence the conclusions to be drawn from the records, are dis- cussed somewhat at length. By this means, it is hoped that whatever might otherwise prove to be erroneous or illogical may be removed so that the ultimate conclusions may become rational, trustworthy, and instructive. The following four species and the first two genera are here described for the first time: Carnegiella gracilis, new genus and new species, page 176 Danodes plumata, new genus and new species, page 182 Onchocalanus nudipes, new species, page 199 Scolecithricella spinacantha, new species, page 208 APPARATUS AND METHODS Nets The townets used on the Carnegie were the ordinary conical one-meter and half-meter nets of fine-meshed bolting silk. These were reinforced in the usual manner with canvas at either end and with both circular and longitudinal ribs of stout tape in the space between the canvas ends. The same nets were used throughout the entire cruise and always in the same manner, to insure a uniform basis of comparison between the different tow- ings. These nets could not be closed, but remained wide open while being lowered to and raised from the 50- meter and roo-meter levels. They were carefully cleaned after every towing so that there should be no mixing of species from different stations. [The following description of the nets used on the Carnegie is from H. R. Seiwell’s article “Patterns for conical silk plankton nets of one-meter and half-meter diameters” as published in Jour. Conseil Internat. Explor. Mer, vol. 4, pp. 99-103 (1929).—Eb. | The nets are of sizes (a) one-meter diameter and 4/4 meters long (the Michael Sars net), and (4) one-half meter diameter and 2% meters long. Both were made from silk bolting-cloth of different meshes with canvas-collars at the top and bottom to hold the net-ring and collecting bottle, respectively. The nets (@) were made in three different meshes and the nets (4) in two different meshes since the filtering characteristics of a net must be according to the kind of plankton to be collected. Dufour silk bolting-cloth of sizes oooo(XX), o(XX), 2(XX), 5(XX), 10(XXX), and 15(XXX) was used exclu- sively for the filtering surface, and eight-ounce double-filled, white, extra duck for the canyas-collars. The seams were taped with inch-wide, fine woyen linen or cotton tape, and the silk was sewed with the best quality No. o machine twist- silk thread. Fine woven cotton tape 114 inches wide was used for the three-meter horizontal seam which also served to hold the small brass rings to guide the throttle-line. One- inch pearl buttons of good quality were sewed with a strong linen thread to the double canvas-collar, all button holes being machine-made. The one-meter (outside diameter) brass rings for nets (a) were made of three-quarter-inch rod and the half-meter (out- side diameter) brass rings for nets (4) of half-inch rod. The silk pieces were joined together by a one-inch French seam, which was taped on the outside and held in place by two additional rows of stitching. . . . Three sizes of silk were used in making the Michael Sars net one meter in diameter at the mouth, tapering to a diam- eter of 0.10 meter, and 4.5 meters long, in the following combinations. Section Combination ae ~ I 2 3 (1) Upper, 0.5 meter long.. 0000(XX) o000(XX) 0000(XX) 10(XXX) 15(XXX) 5(XX) 10(XXX) o(XX) 2(XX) (2) Middle, 1 meter long... (3) Lower, 3 meters long. . Two sizes of silk are used in the one-half meter net which is one-half meter in diameter at the mouth, tapering to a diameter of 6 cm, and has length of 2.75 meters. . . . These nets were used in the following combinations: (1) upper section of length 0.75 meter made of silk bolting-cloth of size 5(XX) and the lower section 2.0 meters long of size 10(XXX); (2) the upper section of length 0.75 meter made 2 COPEPODS OF LAST CRUISE OF CARNEGIE of silk bolting-cloth of size 10( XXX), and the lower section 2.0 meters in length of size 15( XXX). Loca.itigs Tows were taken at each of the 162 stations designated on the accompanying map (map 1), though tows at only 158 regular stations were considered.’ Enough others were taken between the stations to bring the total of the localities up to 208. Not including 3 localities in the North Sea, only 39 of these localities are in the Atlantic Ocean, the remaining 166 being in the Pacific Ocean. As a result the Pacific is well covered from 52° north latitude to 4o° south latitude, but in the Atlantic the stations are all north of the equator. This disparity was not inten- tional, but was due to the unfortunate destruction of the Carnegie at the close of the first half of her cruise. The second half of the cruise had been planned to include the southern part of the Pacific between 40° and 60° south latitude, the South Atlantic from the equator to 60° south latitude, and the entire Indian Ocean. This would have furnished data of supreme value for a comparison of the plankton of the three oceans. It is fortunate that, in accordance with the Carnegie’s rule to forward imme- diately to Washington at each port of call all accumulated data and collections, no data or plankton collections were lost at Samoa in the destruction of the vessel. Dertu oF Tow At each of the regular stations three tows were taken, one at the surface, a second at 50 meters, and a third at roo meters. The second and third nets were attached to the same wire; the surface net was on a separate wire, but was towed simultaneously with the other two. All the nets were drawn horizontally for a sufficient distance to obtain an excellent sample of the plankton at each of the three depths. The length of the tow varied consider- ably and is recorded for the Pacific stations only (pp. 42- 168). All the tows between the regular stations, with one or two exceptions, were taken at the surface only when the vessel slowed down sufficiently or was becalmed. No vertical tows were made, with the single exception of one at station 64, and this was also the only one below 100 meters in depth. Time oF Tow All the tows at the regular stations were started at 8"30™ a.M. local mean time, the time of completion varying with the length of the tow. Thus they were all daylight tows taken at about the middle of the forenoon, and none taken during the afternoon, evening, or night. This regu- larity of the time of the tows adds greatly to their value for purposes of comparison. The surface tows between stations, being dependent on the slowing down or becalming of the vessel, never came regularly but were taken at any time during the twenty-four hours, most often at night. They thus supply valuable data with reference to the migration upward of certain species of copepods during the night. VotumeE or Tow (Paciric Stations ONLY) The volume of the tow was computed by allowing it to settle to the bottom of the bottle and measuring its depth. However deficient this method may be with refer- ence to the actual bulk of the plankton, it does supply a reliable basis of comparison when followed uniformly. When considered in connection with the length of the tow, it furnishes an accurate estimate of the comparative richness of the plankton in any locality. QUALIFYING CONDITIONS Nets It is stated above that the nets used in the 50- and 1oo- meter tows could not be closed while being lowered and raised. In other words, these two deeper tows were not exclusively horizontal, but included also a vertical or diagonal tow to the surface. This means that copepods could get into them at levels nearer the surface than the recorded depth of the tow. In all probability such intrusion of individuals from a 1 For stations 129, 131, 161, and 162, apparently Dr. Wilson did not find any material for this report—Ep. different level actually occurred more or less frequently. But the percentage of these aliens is small, as can be seen by the number of species in each station list recorded exclusively from the two upper levels. Any species con- fined to the 50- or 100-meter level would not be affected by other species coming in from higher levels. But if even one or two specimens of a species which was really con- fined to the surface got into the 50- or the 100-meter net, it would indicate the presence of that species at a level where it did not really occur. The comparatively small percentage of species found at all three levels and the comparatively large percentage of species confined to a OcOI-QcOr ‘a1S9u.7 IYI JO TTA eIN1d ‘suONRs stydeaBourIdQg “1 avyy JIA HOINAVD ©7150 208 ~ 4 COPEPODS OF LAST CRUISE OF CARNEGIE single level are good proof that the mixing of different levels was rare. The relative abundance of any species at different levels will also prove helpful in deciding where it really belongs. For example, suppose a species is sufh- ciently abundant at the surface to constitute 80 or go per cent of the surface tow, as sometimes occurred, and only one or two specimens are found in the tows at lower levels. It is reasonable to infer that the latter specimens do not really belong to the deeper tow, but entered while the net was being raised or lowered. There will neces- sarily be some mixing of levels, but it is so slight as to be practically negligible, and none of the important results here considered is at all affected by it. Depry or Tow Since the lowest depth at which tows were taken (with one exception) was 100 meters, whereas the depth of the bottom at all but 5 of the stations ranged from 2000 to 8000 meters, it follows that the entire towing was prac- tically at the surface. We are concerned here, therefore, with the epiplankton exclusively, and not at all with the bathyplankton. This means that the range of the species here recorded must be regarded as essentially a surface- area distribution, and only incidentally as a depth distri- bution. This consideration is of special importance in comparing the present records with those of other expe- ditions, notably the Challenger, Siboga, and bathypelagic Monaco expeditions. It is obvious that none of the numerous rare and often unique species obtained at depths ranging from several hundreds to even thousands of meters can be expected in these surface tows. Their absence from these records, therefore, is no indication that they were not present at the localities examined, but simply that the nets did not descend far enough to secure them. On the other hand, the presence in these tows of certain species obtained by other expeditions in vertical tows starting from considerable depths shows that such copepods cannot be regarded as exclusively bathypelagic. The Siboga expedition yielded the largest total of species thus far recorded. But at every station of that expedition whose record of species totaled above 70, the towing was done with a Hensen vertical net starting from depths of 700 to 2000 meters. These same deep ver- tical tows included most of the new species that were obtained. In view of these considerations, the facts that the Carnegie stations from 35 to 44 inclusive averaged 83 species, and that several other stations yielded species totals of from go to over 100, assume a greatly enhanced significance. These facts should be kept constantly in mind also when comparing the Carnegie records with those of the Challenger, Siboga, and Monaco expeditions. SuPPLEMENTARY Dara In the station lists of species herewith presented there are included statistics regarding certain factors which have considerable significance in copepod distribution. The Carnegie Institution of Washington has furnished the author with blueprint lists showing the temperature, salinity, density, and hydrogen-ion concentration of the sea water at the three tow depths for each station. These data are reproduced here, but those pertaining to condi- tions of the weather, sky, and sea at the various oceano- graphic stations are not given in this report inasmuch as they are to be published in other volumes of this series giving the observed data and discussions relating to physical oceanography and to meteorology. A second blueprint list supplies for the Pacific stations (35 to 162) the total volume of the plankton for each of the tows and the distance through which the net was drawn to secure that volume. The data for volume and distance are not available for the 34 Atlantic stations except in one or two instances. The lists of copepod species from the three tows at each station have been kept separate, and there is also recorded the comparative abundance of each species at the three depths. All these data are incorporated in each station list be- cause it is believed that they are fully as valuable as the lists of species themselves. As far as is known, such data have never before been presented in connection with station lists. They furnish practically all the information that can be obtained with reference to each locality. Without them the list is devoid of any information ex- cept the mere names, and becomes practically meaning- less. OcEANIC CURRENTS The surface currents of both the Atlantic and Pacific oceans were fairly well known and had been charted before this cruise of the Carnegie. The observations taken during the present cruise confirm previous discoveries and add a great many of the missing details. Very much less is known about the deep-sea currents, but since all the Carnegie tows were confined to the upper 100 meters of water, these deeper currents would not affect them so much as would those at the surface. The thing that con- cerns us most in dealing with the copepods is the evi- dence of an intimate relation between the surface cur- rents and plankton distribution. The only surface current of any importance in the North Atlantic is the well known Gulf Stream. This was crossed several times by the Carnegie, and its influence was chiefly manifested in an increase of the copepod plankton, both in species and in numbers. There were COMPARISONS OF PLANKTON 5 also some of the usual instances of a northward trans- portation of species whose normal habitat was farther to the south. The course of the Carnegie in the Atlantic did not come in contact with other surface currents, and con- sequently the station lists of copepods cannot give us more than this minimum of evidence with reference to the influence of the currents on the plankton. A similar relation between the Gulf Stream and the volume of the plankton was shown by Jespersen (1926) in his discus- sion of the quantity of macroplankton in the North Atlantic, but species were not mentioned. In the Pacific Ocean, however, conditions are very different. In one of the papers already published by the Carnegie Institution of Washington, Sverdrup has made use of the map of the surface currents of the Pacific which is here reproduced (map 2). This map shows an approximately symmetrical surface circulation north and south of the thermal equator, which is a few degrees north of the geographic equator. In the South Pacific the west-wind drift generates a current flowing east and striking the western coast of South America, where it is deflected to the north along the coast as the Peruvian Current. At the equator this current is turned back west- ward across the central Pacific as the South Equatorial Current. A part of it flows directly west to the East Indies, another part flows southwest to Australia. In the North Pacific the west-wind drift forms the Japan Current, which flows eastward and, striking the western coast of North America, is deflected to the south as the California Current. This follows the coast to the southern boundary of Mexico, where it is turned west- ward as the North Equatorial Current; this flows directly west to the Philippine Islands, where it joins the Japan Current. Between the two equatorial currents, both of which flow west, is a countercurrent flowing east along the thermal equator and striking the western coast of Central America. Here it divides, one half turning south and then west and joining the South Equatorial Current, the other half turning north and west and joining the North Equatorial Current. The course of the Carnegie followed part of each of these currents. Stations 35 to 4o were in the half of the eastern end of the Counter Equatorial Current that turns south and west. Stations 40 to 80 were within or close to the Peruvian Current. Stations 93 to 98 were in the South Equatorial Current. Stations 102 to 110 were in the North Equatorial Current. Stations 111 to 115 were in the Japan Current. Stations 128 to 135 were in the Cali- fornia Current. Stations 150 to 160 crossed the North and South Equatorial and the Counter Equatorial currents. The above stations in every instance were the ones that yielded the greatest variety of copepod species and the largest number of individuals. There must be something, therefore, in connection with these currents which is con- ducive to copepod life and development. Sverdrup has plainly shown a combination of low salinity and low temperature near the surface in the Peruvian Current, and this combination appears to a greater or lesser degree in each of the other localities mentioned above. We cannot escape the conclusion that such a combination is favorable to the copepods, or at least not antagonistic. There is also the probability of better aeration of the water in these currents than outside of them, and the possibility that they contain a richer and more uniform supply of food than can be found in water that does not flow. COMPARISONS OF PLANKTON Since all the regular tows were made at the same time of day, by the same persons, using the same nets, and employing the same methods, the species lists will be as free from diversity as they could possibly be. If we com- bine with these lists of species the supplementary data mentioned above, we find ourselves in possession of an accurate and really scientific basis for a comparison of the copepod plankton of the two oceans and of the dif- ferent parts:of each of them. CoMPARISON OF THE Two OcEANS The Carnegie towings show that the Pacific plankton is much richer in copepod species than that of the Atlantic over those parts of the two oceans covered by the cruise. For instance, station 34, the last one in the Atlantic, may be compared with station 35, the first one in the Pacific. These two stations are about equally distant from the two ends of the Panama Canal; the bottom depths are each over 3500 meters, with a difference of only 47 meters. The Atlantic station yielded 48 species; the Pacific station yielded 96 species. On comparing sta- tions 15 to 25, down through the center of the North Atlantic, with stations 130 to 135 and 148 to 152 at cor- responding latitudes in the Pacific, we get a total of 394 species for the Atlantic stations with an average of 36 per station, and 661 species for the Pacific stations with an average of 66 per station. Unfortunately the total volume of the plankton is not recorded for the Atlantic stations, but in view of the great inferiority in number of species it is reasonable to assume that it was much less than that at the Pacific stations. uesd¢Q) WYK IY] JO syusIINI sdejANg “ct dv (SNOILVLS |SIHdvHYSONW3DO0 SISSNUVS 3LVDIGNI $379uI9 wove) 2 pn ND WIN Tomusssaatlpsiters) ONOD33S Y3d S¥3L3WILN3D G y SUASWON AG ALIDONSA-LN3YYND ONY SMOXYY AG GSLVDIGNI NOILDSYIG-LN3yuND wpeomag “bry PP J Mpanowo op it opsFig #11 aL 4 COMPARISONS OF PLANKTON 4 The largest number of species at a single station in the Atlantic was 60, at station 23, and half the stations had each a total of less than 25 species. Pacific station 56 yielded 108 species; 14 stations yielded 80 to 96 species each, and 17 stations from 71 to 78 species each. At only 15 (12 per cent) of the 124 Pacific stations did the species total fall below 25. The entire number of different species obtained from all the Pacific stations was 265, whereas the Atlantic stations yielded only 132. Thus in the Car- negie towings the Pacific yielded, on the whole, roo per cent more copepod species than the Atlantic. But there are some excellent reasons why this ratio, although it is entirely correct for the Carnegie material, should not be too hastily adopted as true for the entire plankton of the two oceans. In the first place, only a part of the North Atlantic was covered by the Carnegie tow- ings. If the North and South Atlantic had been as com- pletely towed as were the North and South Pacific, the result would certainly have been different. In other words, the comparison is only a partial one. In the second place, the cruise of the Carnegie covered those parts of the Pacific which have been found by other investigators to be most prolific in copepod species. On the contrary, the parts of the North Atlantic that were included are regarded as the least prolific by all who have investigated the Atlantic plankton. The comparison, therefore, not only is incomplete, but also favors the Pacific to a con- siderable degree. Jespersen (1926), in discussing the quantity of macroplankton obtained in the Atlantic by Danish investigators, concluded that the minimum volume in the upper 100 meters was to be found in the western Atlantic between 20° and 30° north latitude, in the Caribbean Sea, and in the Sargasso Sea. The last two are the parts traversed by the Carnegie, which did not touch the regions of maximum volume. Jespersen stated that around the Azores the volume of plankton was 20 to 30 times as large as in the Sargasso Sea. If the region of the Azores, therefore, and other more prolific regions of the Atlantic had been included in the cruise of the Carnegie, the comparison of the plankton of the two oceans would have been much less favorable to the Pacific. In the third place, as has already been shown, more than half the Pacific stations came within the in- fluence of surface currents, whereas only a few of those in the Atlantic were so situated. If these currents are really as conducive to copepod plankton as they appear to be, this is another advantage for the Pacific. All these reasons are well worthy of consideration, but in spite of them it does not seem as if the inclusion of the more prolific parts of the Atlantic would produce enough additional species to take away the supremacy established by the Carnegte material for the Pacific. In looking for an explanation of the small number of species found in the Sargasso Sea and in the Caribbean Sea, we may note that at the stations which are compared above we find in the Atlantic a comparatively high temperature combined with an exceptionally high salinity. A high salinity is known to be adverse to ordinary pelagic copepods, and it is possible that when combined with a fairly high temperature it may become a deterrent to copepod life in the epiplankton. It is worthy of comment that there was not found in the Pacific any trace of such countless swarms of a single copepod species as are often seen of Calanus finmarchicus at certain seasons in the North Atlantic. They may exist in the Bering Sea north of the Aleutian Islands, but this region was not visited by the Carnegie. CoMPARISON OF DIFFERENT REGIONS OF THE PACIFIC Although the Carnegie towings thus are inadequate for a satisfactory comparison of the plankton of the two oceans, they do furnish an ideal basis for comparing the copepod faunas of the different regions of each ocean, especially of the Pacific. They are extensive enough to include adequate samples from practically all the im- portant regions of the ocean, and at the same time they furnish enough data with reference to the environment in each of the regions to explain the differences that appear. As has been found by all other investigators, the trop- ical parts of the ocean are richer in species than the tem- perate regions, but the tow is often inferior in volume. The plankton of the South Pacific contained a greater number of species than were found in the North Pacific, but the volume of the tow reached its maximum in the northernmost part of the ocean. In the South Pacific the stations yielding the most species were located in the eastern part alongside the Humboldt Current and in the western part north of the Samoan Islands. In the North Pacific the richest stations were found off the coast of Japan in the western part, and halfway between San Francisco and the Hawaiian Islands in the eastern part. Station 56, situated in latitude 31° 49’ south and longi- tude 109° 04’ west, yielded 108 species and becomes thereby the banner station of the entire cruise. Station 35, outside the Pacific end of the Panama Canal, was second with 96 species, and station 113, close to the eastern coast of Japan, was third with 93 species. Stations 40 and 109 were fourth, each with go species. The last of these, num- ber 109, was the station above the newly discovered Fleming Deep, the depth of the bottom being 5252 meters. There were g stations each yielding from 80 to 88 species, 18 stations each with 71 to 78 species, 16 stations each with 60 to 69 species, and 26 stations each with 50 to 59 species. This makes a total of 73 stations, or 59 per cent 8 COPEPODS OF LAST CRUISE OF CARNEGIE of those in the Pacific, each listing 50 species or more. In the Atlantic, the Caribbean Sea stations yielded a larger number of species than those in the Sargasso Sea. But, as already stated, both these regions were found by Jespersen (1926) to be much inferior to other parts of the North Atlantic. Diversiry oF DistriBuTION We have just seen that there is great disparity in the quantity of macroplankton obtained from different localities of the various oceans. In dealing with the copepods we may go farther and say that there is not a single species that does not show more or less diversity in its distribution. In more than go per cent of the species the diversity is so great that it becomes the predominant feature of the distribution. This diversity is evident not only in the horizontal or geographic distribution, but even more in the vertical distribution, as will be shown later. Any attempt, therefore, to calculate the number of copepods per liter or per cubic meter of the ocean water gives us no practical information. One might as well try to calculate the number of gulls and terns per cubic meter of the atmosphere above the ocean. The recurrence of specific names in successive station lists might suggest at first thought a more or less uniform distribution. But when we consider the relative abun- dance, we are likely to find that the species was repre- sented at one station by hundreds of individuals, whereas perhaps at the very next station the entire tow had to be carefully examined in order to secure a single specimen. The concept of diversity is greatly strengthened by a study of the data contained in the station lists here recorded, especially those on relative abundance. Simply the name of the species has heretofore been recorded, and usually we have been left in complete ignorance of its comparative abundance and its vertical distribution. The interesting and valuable information which may be derived from such data furnishes an abundant warrant for their publication. Of the 263 different species recorded from 166 localities in the Pacific Ocean, 105 appear at 5 localities or less, 60 being each confined to a single local- ity. Of the remainder, 120 species are restricted to a total of 50 localities or less, which is only a two-sevenths dis- tribution. Only 7 species, or less than 3 per cent of the entire number, have any claim to universal distribution, and each of them shows great diversity in its relative abundance. A remarkable instance of inequality in distribution is shown by two surface tows taken between stations 50 and 51. The tows were made consecutively at the same locality, on the same day, and with the same net. To- gether they yielded 42 species, and 23 of these, or more than half, were found in one tow only and did not appear at all in the other. Two surface tows between stations 62 and 63, taken on the same day, with the same net, but a short distance apart, yielded 50 species, 32 of which, or 64 per cent, were confined to one of the tows. Between stations 63 and 64 three surface tows were made on January 2 and three others on January 3, all with the same net, but short distances apart. The first three tows yielded 44 species, of which 26 appeared in one tow only. The second three tows gave a total of 37 species, and 22 of these were found in one tow only. Such data not only confirm the irregularity of distribu- tion in the plankton, but also suggest that, even in restricted areas, what may be termed the “personnel” of the plankton is constantly changing. Two tows over the same area, no matter how quickly one may follow the other, will never yield identical results. Having thus established the lack of uniformity in the horizontal or geographical distribution of the copepods, we turn to their vertical distribution. Daytime STRATIFICATION The different species of copepods that are found near the surface of the ocean in the daytime show a marked tendency to arrange themselves in zones or layers parallel with the surface. Some species are practically confined to the surface tows, of which they often constitute a very large percentage, rarely as high as go to 95 per cent. Others are confined entirely or very largely to the 50- meter tow, and still others apparently do not approach nearer to the surface than the 100-meter tow. If the station lists are compared, it will be found that this stratification is apparent in every one of them. Per- centages large enough to constitute definite evidence of layering are always present. This does not necessarily mean that any one species is always and everywhere found at one of the three depths and never at either of the other two, although even that is true in some instances. But it does signify that at the time the tow was taken and under the existing conditions, very re- spectable percentages of the copepods showed a decided preference for one of the three depths to the exclusion of the other two. On an average, about half the copepods present at each station show such an exclusive preference, and most of the other half show a similar but less marked liking for some one of the zones. They are found in abundance in the preferred zone, but only rarely or in small numbers in the other two zones, being often wholly absent from one of them. In all probability a closing net would eliminate many of these secondary appearances and credit more species with exclusive preference for the zones where they were most abundant. Two or three COMPARISONS OF PLANKTON 9 examples will illustrate the evidences of such stratifica- tion more clearly. The list for station 35 shows 10 species confined to the surface tow, 13 to the 50-meter tow, and 24 to the 100- meter tow. Forty-seven species, therefore, out of a total of 96 showed definite selection of a single depth to the exclusion of the other two. Thirty other species were found in two of the tows but not in the third one, thus manifesting a similar but less exclusive selection. Fur- thermore, in only 2 instances do we find the abundance records of any species in the two tows exactly the same. In 7 other instances, however, both records are expressed in numerals, with not enough difference between them to warrant any assumption of real preference. Eliminating these g records, the other 16 species do manifest a more or less decided preference for one of the two depths over the other. Finally, there were 19 species which were found at all three depths. In 5 instances the abundance record was exactly the same at the three depths. For 9 other species it was the same at two depths and differed in the third. In the remaining 5 species the records show a de- cided preference for one depth over the other two. Of the 96 species taken at this station, therefore, 68 (71 per cent) showed good evidence of selection in the depth at which they were found. In the list for station 56, 49 species were restricted to a single depth, 44 were taken at two depths but not at the third, and 15 were present at all three depths. Of the 44 two-depth species, 19 showed a definite preference for one depth over the other, and of the 15 three-depth species, 11 distinctly favored one of the depths in prefer- ence to the other two. Here, then, 79 species (73 per cent) manifested a choice of depth. At station 51, 39 of 50 species were confined to a single depth; 10 others were present at two depths, with 6 of them preferring one of the depths to the other. A single species was found at all three depths, with the same record for two of them and a much smaller one for the third. Here, then, 45 species (go per cent) showed selec- tive stratification. Every one of the lists gives evidence of similar stratifi- cation of the copepods captured at the station. The num- ber of species manifesting an exclusive preference for one depth only and those that were present at all three depths are recorded in the remarks accompanying each station list. The former constitute from 50 to 90 per cent of the species total in three-fourths of the station lists, and in the other fourth they fall below 4o per cent only twice. The species present at all depths vary from 0 to 30 per cent of the species total, with an average of about 15 per cent. Among these species the number of instances in which the abundance record is the same for all three depths is so small as to be practically negligible. Sum- ming up the evidence here presented, we find that almost every species in each of the station lists shows some degree of preference as to depth. Causes OF DayTIME STRATIFICATION We naturally look for the cause of this universal day- time stratification within the upper 100 meters of the ocean. Is it the salinity, the temperature, the density, the hydrogen-ion concentration, any combination of two or more of these factors, or the united effect of all of them? Or may it be something outside, more powerful than any of them, or even than all of them combined? Since we have the necessary data in connection with the station lists, some answer to these questions ought to be possible. Let us consider the data separately, beginning with tem- perature. Temperature There is no doubt that temperature does exert con- siderable influence on copepod distribution. Is it strong enough to produce such a universal stratification? And if so, is there sufficient difference in temperature between the three depths at which the tows were taken to warrant its selection as the principal cause? At first it would seem as if the answer might be in the affirmative. The greatest variations in temperature of the ocean water are nearest the surface. The upper 100 meters, within which all but one of the Carnegie tows were taken, show the maximum differences between the various regions of an ocean—polar, temperate, and trop- ical. Here also are found the maximum differences in temperature between the vertical depths 0, 50, and 100 meters. Below 100 meters there is a gradual approach to uniformity of temperature over the entire area of all the oceans. Variations in temperature are undoubtedly one of the causes of the marked differences in the copepod species that make up the regional plankton of the upper roo meters. The Carnegie stations in the Pacific ranged from 52° north latitude through the tropics to 40° south lati- tude. The low temperatures of the upper 100 meters north of parallel 40° north entirely exclude many of the copepods that are common in the tropics. The number of species taken at each of the 12 stations in that part of the Pacific was thus reduced to an average of only 16. A comparison of this average of 16 with the average of 83 for stations 35 to 44 in the tropics suggests the powerful influence of temperature on regional distribution. Is its influence on vertical distribution equally great? These few species at the northern stations showed the same evidence of stratification as the more numerous species in the tropics. That this stratification is not due to the ver- Io COPEPODS OF LAST CRUISE OF CARNEGIE tical differences in temperature, however, is apparent on examination of the station lists. At station 121, for ex- ample, the three tows yielded 18 species of copepods. Two species only were found at the surface, one of which was represented by development stages only, with no adults. Eleven species were present in the 50-meter tow, and 16 in the roo-meter tow. Two of the former and 6 of the latter were not present in either of the other two tows. The temperature at the surface was only 7°4 C; at 50 meters it dropped 4°, and at 100 meters 1°5 more. If the variation in temperature were the reason for the copepods’ choice of depth, the 16 species should have been found at the surface and not at the 1oo-meter level. More- over, a difference of only 1°5 would hardly be sufficient to cause a third of the entire number of species to locate at the 100-meter level to the exclusion of the 50-meter level. At station 127, 14 species were obtained; 6 species were present in the surface tow, 6 in the 50-meter tow, and 10 in the roo-meter tow. Three species were confined to the surface, 1 to the 50-meter level, and 5 to the 100-meter level. The temperature at the surface was 13°3 C; it dropped 3° at 50 meters and 2° more at 100 meters. The same considerations as before preclude the assumption that the variation in temperature was the cause of the differences in depth of the copepod species. Any copepod that has become inured to living and breeding in water as cold as is found in these northern latitudes will not be much affected by changes of 2° or 3° in temperature. In the tropics, on the other hand, the water at the sur- face is much warmer and the differences in temperature between the three tow depths are sometimes large enough to appear like important factors in copepod zoning. At station 35, for instance, the temperature at the 100-meter level was 13° lower than at the surface. At station 39, on the equator, it was nearly 11° lower; at stations 71 and 72, latitude 10° south, it was about 10 lower. At station 109, over the Fleming Deep, there was a drop of 8°, at several of the stations north of the Hawaiian Islands the drop was 7° to 9°, and at a few stations southeast of the Hawaiian Islands there was a difference of 8° to 16°. These variations are all of sufficient magnitude to suggest an appreciable influence of temperature on stratification. An examination of the species lists at these stations re- veals exceptionally well marked stratification, but in every instance it is the exact opposite of what it should be, on the hypothesis that higher temperature induces greater concentration of copepods. The species were bunched at the two lower levels instead of at the two upper ones, and the 100-meter tow contained sometimes two or even three times as many species as were found at the surface. At station 152, the water at 50 meters was 13° colder than at the surface, and at the 100-meter level it fell 3° more, a total drop of 60 per cent. Yet the 100- meter tow contained almost three times as many species as the surface tow, and the 50-meter tow nearly twice as many. Frequently, however, the tropical stations showed but little temperature change at the three tow depths. At station 46, for example, the difference in temperature between the surface and the 1oo-meter depth was less than 1°. Yet 4 species were restricted to the surface tow, 5 to the 50-meter tow, and 13 to the 100-meter tow. At stations gt and 93 the difference in temperature between the two tow depths (o and 50 meters) was 0-2, but 80 per cent of the copepod species were present in one tow and absent from the other. At station 80 the difference in temperature between the two depths was only o°1, but 11 species were confined to the surface tow and 23 to the 50-meter tow. A difference of 0-1 in temperature would hardly constitute a sufficient incentive for the exclusive stratification of 63 per cent of the 54 species ‘captured at this station. At station 81 exclusive stratifica- tion was shown by 70 per cent of the 47 species, with only o-1 difference in the temperature of the two tows. At station 82 there was absolutely no difference in tempera- ture at the two tow depths, and still 70 per cent of the 52 species showed a definite choice of one of the depths to the exclusion of the other. At station 160 the temperature was exactly the same at all three depths, but 50 per cent of the species were confined to a single level, and 25 per cent more were present in two of the tows but absent from the third. Three-fourths of the species thus showed definite zoning without any temperature incentive. We are forced to conclude, therefore, that in most cases the temperature variation is not large enough to produce the amount of stratification shown; and when it does appear to be of sufficient size, it seems to have the opposite effect from what would be expected. In this connection it must be noted that some copepod species are not influenced by even considerable changes in temperature, and that many of them appear immune to low temperatures. Expeditions into both the Arctic and Antarctic regions have revealed species of copepods, accustomed to warmer regions, living in the icy waters of those regions, and apparently breeding freely. The same is true of the copepods that live at considerable depths in the temperate and tropical regions. A tow was taken July 20, 1933 in a closed net south of Georges Bank about 39° north latitude at a depth of 2000 meters. The net worked perfectly, going down closed, opening at the desired depth, and closing again before being drawn up. An examination of this tow revealed hundreds of Metridia belonging to four different species, and also specimens of Rhincalanus, Eucalanus, Pareuchaeta, Centropages, Het- erorhabdus, Lucicutia, Haloptilus, Gaidius, Pseudochi- COMPARISONS OF PLANKTON Il rella, Pleuromamma, and other genera. The temperature at 2000 meters was below 3° C, and yet these copepods seemed as healthy and active as other specimens of the same species captured within the upper 100 meters, where the temperature ranged from 15° to 21° C. It is evident that even considerable variations in temperature would affect such copepods very little, if at all. Salinity (Map 3) and Density In contrast with the temperature, both the salinity and the density differ so little within the upper 100 meters that they probably exert no influence on the vertical dis- tribution of the copepods. But they do appear to affect the regional distribution to a certain extent. The surface salinity is a little higher in the Atlantic than in the Pacific Ocean, which may be a contributing factor in the superior quantity and variety of the Pacific plankton. None of the Carnegie stations came within the area of maximum sur- face salinity in the North Atlantic, but those numbered from 22 to 34 were in the zone of minimum salinity, and it is worthy of note that they yielded a larger average number of species than any of the others. Again, the area of maximum salinity in the Pacific Ocean lies around the Society Islands. The Carnegie passed through this area, and the station lists from within it are below the average. All the stations where the largest numbers of species were obtained show salinities at or a little below the average. This would seem to indicate that such average salinities are most acceptable to copepods and that there is a tendency to avoid both extremes. The salinities and densities at the three tow depths are exactly the same in many of the station lists. When they do differ, it is within such narrow limits as to preclude any appreciable in- fluence on vertical distribution. Hydrogen-lon Concentration The same statement may be made about the hydrogen- ion content of the sea water as about the salinity and density. The hydrogen-ion concentration is too often exactly the same for all three tow depths, and when it does vary the extent of the variation is too slight to war- rant an assumption that it has any material influence on the vertical stratification of the copepods. Phototropism The preceding discussion has shown that neither tem- perature nor salinity, hydrogen-ion concentration, or density could produce the daytime stratification of which we find definite evidence in every station list of species. Temperature and salinity are concerned in the regional distribution of the species and may answer the question as to why a given copepod is found at one station or in one locality and not in another; neither density nor hydrogen-ion concentration appears to enter appreciably into even this kind of distribution. We are forced to look elsewhere for the cause of the daytime stratification. We must search for something that is everywhere present in the daytime, that is at work all the time from dawn to dusk, and that is strong enough to produce definite and uniform results even in the face of antagonistic influences. The very fact that this is a daytime stratification suggests sunlight as its cause, and after the elimination of every- thing else, this is the only cause left that answers all the requirements that have just been enumerated. It has been found by many observers that light is the most important factor controlling the nocturnal migra- tion of copepods, and it is perfectly logical that it should also control their diurnal movements. Many species of copepods in both salt and fresh water migrate regularly from greater or lesser depths toward the surface as soon as it begins to be dark, and begin to return between mid- night and sunrise. It is evident that the depth from which a copepod will be able to reach the surface is necessarily limited by its swimming ability. The jerky movements characteristic of copepod locomotion are not conducive to even moderate rapidity, and they are never continued steadily for any length of time. The progress is always leisurely, interspersed with frequent rests and periods of floating. The only occasion when a copepod tries to move rapidly is in an attempt to escape impending danger, and even then its efforts are spasmodic and nearly always futile. Moreover, its course is never in a straight line for any considerable distance, but is full of turns and twists and often spiral movements. Another fact must also be considered, namely, that the interval between sunset and sunrise varies greatly with the season of the year and with the latitude of the loca- tion. All the Carnegie stations were located in the tropical and temperate zones. The observations in the North Atlantic were made from the middle of May to the first of October, those in the South Pacific from the first of November to the last of April (southern summer), and those in the North Pacific from the first of May to the middle of October. At practically every one of the stations, therefore, the time of year and the latitude were such as to give considerably reduced periods of darkness, with a corresponding increase in the periods of daylight. Such considerations lead inevitably to the conclusion that the diurnal migrations are confined to the upper layers of the ocean water and do not reach any con- siderable depth. It would. seem as if from 100 to 150 meters were about the lowest depth from which the average copepod would be able to reach the surface. But of course the migration is not limited by the copepod’s ability actually to reach the surface within a given period. It undoubtedly takes place down to the limit of urad¢) dye ayI ur santuyes “€ avy 2°78 3TUIW Y3d NI SINIWA SNOILVLS DIHdVHSONV390 BLVSIGNI S3794ID XOv18 So PE< Vrenenbonge I2 COMPARISONS OF PLANKTON 13 light penetration. Although the copepods taking part in this deeper movement would not reach the surface, they might be found at the 50-meter or 1o0-meter level during the night. If it be true that the coming of daylight furnishes the incentive for the departure of the copepods from the surface, it follows that the depth to which they retire below the surface will vary with the intensity of the light. They will descend farther on a bright, sunny morning than when it is cloudy and lowering. On a day that is ushered in with clouds so dark and gloomy that the sun- shine can scarcely penetrate them at all, the copepods may well stay near the surface long after sunrise and descend but a short distance. The varying intensity of the light offers a good explanation of the fact that some species are found close to the surface at one station and considerably removed from it at another, perhaps the very next one. Damas and Koefoed (1907) summed up their work on the plankton of the Greenland Sea as follows: “At any given place the organisms are distrib- uted according to the degree of light for which they are sensitive. They rise and fall according to the daily varia- tions in light intensity. The level at which a form remains is different from sea to sea. Species which live at the sur- face in the polar sea are found in the depths under the equator. Others that are seen to exist in the intermediate layers in the north are only found in the abyss at the south.” Russell (19276) confirmed these statements and added that copepods also show seasonal variation in their vertical distribution, going deepest in mid-June when the light intensity is greatest. Again, we cannot expect the same intensity of light to affect different species equally, and here we have a reason for the fact which is so evident in every one of the station lists. Some species remain at the surface no matter how intense the light becomes; the others migrate downward but stop at different levels according to the amount of influence exerted on them by the light. We are thus en- abled to understand how it is that the copepods become so distinctly stratified at every one of the stations in the daytime and also why we find the same species concen- trated in different strata on different days. Russell went farther and declared: “In the sea each plankton animal may have its own vertical zone in which it finds certain conditions most favorable. This zone varies for different species, for individuals of the same species at different ages and stages of development, and even for the different sexes.” Although, therefore, this is not the first time that strati- fication of the plankton under the influence of sunlight has been proposed, it is here proved to exist among the copepods over a much more extensive area of two oceans than had hitherto been studied. The fact that every one of the station lists without exception gives definite evi- dence of this stratification would seem to warrant the general statement that it exists everywhere in the open ocean during the daytime. Michael (1913) discovered a similar stratification among the chaetognaths of the San Diego region, California. He concluded that each species had its own definite and specific manner of vertical distribution just as truly as it had its own specific morphological characteristics, and that the two were more or less interrelated. Rose (1925) made an extensive study of the biology of the plankton at Roscoff on the coast of France. He included the entire plankton in his study and, among the other forms, six of the copepods most abundant at that locality. Later he repeated his Roscoff experiments with other copepods at Banyuls-sur-Mer on the Mediterranean. From these ex- periments he concluded that below a certain inferior light-intensity limit the copepods were positively photo- tropic, above a certain superior light-intensity limit they were negatively phototropic, and between the two limits they were indifferent. He concluded that the daily vertical migration is due to the following influences: (1) Sunlight provokes the movement, directs it, and partly regulates it. (2) Temperature modifies more or less the action of the light energy, and when high enough may even reverse the action of phototropism. These inter- actions between temperature and phototropism have been verified by other observers: Parker (1902) found that the females of Labidocera aestiva had a strong positive photo- tropism for light of low intensity, whereas the males had a weak negative phototropism; these were unaltered in both sexes by temperature changes between 10° and 35° C; in a strong light the female became negative, but the male was not affected. Russell (1928) found that Calanus finmarchicus was negative to light at medium tempera- tures but became positive at 13° C and strongly so below 10° C; Metridia lucens was negative at ordinary tem- peratures but became positive at 10° C; Acartia clausit was strongly positive at ordinary temperatures but the phototropism entirely disappeared at 28° C; Centropages hamatus was positive up to 25° C, then became more and more indifferent to light and was finally negative. (3) Salinity, chemical composition, dissolved gases, etc. are accessory factors but usually have little if any influence. In exceptional conditions they may become of great im- portance. These experiments were made near the shore in comparatively shallow water, where physicochemical conditions would have a somewhat increased influence. In the open ocean the influence of the temperature and accessory factors would be considerably reduced and that of the sunlight correspondingly increased. Rose (1925) suggested that the majority of the animals in the plank- ton are adapted to an optimum intensity of light, and 14 that this varies with each species and possibly with each individual, and is affected by the physicochemical factors of its environment. The optimum zone of distribution changes with the age of the animal and with its physico- chemical state at any moment. This explains the fact that nearly all the copepods show a strong positive photo- tropism during their development stages, although many of them become negatively phototropic on reaching maturity. Russell (19274) confirmed this and added: “The gradual changes in vertical distribution throughout the life of an individual have been termed ontogenetic migrations.” Russell (1925, 1926a, 19268, 1926c, 19274, 1928) has pub- lished several papers on “The vertical distribution of marine macroplankton.” He deals with the entire plank- ton, especially the young of fishes, and devotes one paper to light intensity as a controlling factor in plankton dis- tribution (1926c, p. 415). He gives the vertical distribution of Calanus, Centropages, and Temora in water over 50 meters deep, at different hours of the day, under different intensities of light, and during different months of the year. We gather from these that the vertical distribution sometimes begins below the surface, attains its maximum at depths of 5 to 20 meters, and then diminishes and dis- appears before reaching a depth of 50 meters. This distri- bution was in water which was shallow as compared COPEPODS OF LAST CRUISE OF CARNEGIE with the open ocean, but there is no reason why it should not occur also in the open ocean at least to some extent. If it does, then we should find communities in the 25- meter zone differing more or less from those at the sur- face and at the 50-meter level. In all probability, there- fore, a tow taken at the 25-meter level would contain species not found at the surface or at the 50-meter level. Similarly, the 75-meter level would probably be found to contain species different from those of the 50-meter and 100-meter levels. We are thus forced to the inference that the Carnegie towings probably did not obtain all the species that occur within the upper roo meters of the ocean water. Incidentally, also, these considerations indicate the in- adequacy of results obtained by daytime towings at the surface alone in an effort to determine the plankton of any given locality. The number of species thus obtained would constitute so small a fraction of the entire plank- ton at the locality that it would have but little value. A surface towing in the night, on the contrary, might give a very respectable indication of the total plankton, since many of the species that remain at deeper levels during the daytime come to the surface at night. To obtain satis- factory results, therefore, there must be tows at different levels during the daytime and these must be supple- mented by tows at or near the surface at night. LISTS OF SPECIES BY STATIONS As already stated, the station lists which follow contain all the available data for each station in reference to tem- perature, salinity, density, and hydrogen-ion concentra- tion. In addition, every species is recorded from the depth or depths at which it was obtained, and its relative abundance is given. For 5 specimens or less, the actual number is given. Above that number, the letter + (rare) indicates 6 to 10 individuals; f (few), 11 to 24; ¢ (common), 25 to 50; and a (abundant), over 50. Actual count was made up to 25; above that, the numbers were estimated. This method of record gives us not merely the regional dis- tribution, but also the vertical distribution at each station, and reveals very clearly the stratification or layering of the copepod species during the daytime. Attention is again called to the fact that the three tows at all the regular stations were made at about the same time of day, which adds greatly to their value for purposes of comparison. In the remarks under each of the station lists are noted the important data for that station. The total number of species found at each depth is also given, together with the number and percentage of species which were con- fined to a single depth as well as the number found at all three depths. Comparisons are also made between the tows taken at the regular stations in the daytime and the surface tows made between stations, usually during the night. In many instances these comparisons reveal noc- turnal migrations to the surface on the part of some of the species. STATION 1 May 12, 1928; 38° 14’ N, 67° 34’ W; bottom depth, 4900 m; 49 species Depth of tow, m 0 70 Depth of tow, m 0 70 Temperature, °C 24.0 OPN) Density (orp) 24.5 D5) Salinity, 0/00 36.2 36.4 Hydrogen-ion concentration (pH) 8.16 8.17 BRERA CRATES EEDNITA Operate 2719 m; 21 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 15.0 14.6 13.5 Density (1p) 26.6 27.0 27.4 Salinity, 0/oo 35.8 36.0 35.8 Hydrogen-ion conc. (pH) 8.19 8.21 8.15 Acar tice clattsiikew-geeetc tial strstr ore f r Oithonayplumifera......-2.. 42 r f longiremisas seer ee ie r SCBISOM eyo. ee oss) c1sials-s0 8 isecepae es f Calanus helgolandicus........... r SUMMELES ep esp rouse oie ans Ristetechactas a a a MINOKs Ses els wiae swine es oe f @Oneaeabmuinutae 2. ee oetewieree f Ealocalanusipavorncseeneeecir oe aie r VEINS Lalcrpency cts tei crs, cts laos eseyens r : a Centropages furcatus............ r Pseudocalanus minutus......... xe f if Clausocalanus arcuicornis........ c @ f Rhincalanus nasutus............ f r Rarranulaicantnatals essen cece a iF Sapphitinayangustase s,s sso. f fej) 0) Ely nian aeecccara ce eetcetie f Highomaculatary «es -jtetree ey. i Mecyneceraiclausiz see eee ae c c c stellatamprcmrasecc sts clades iP c Microsetella norvegica........... The temperature varied only 1°5 in the upper 100 meters, and the salinity and hydrogen-ion concentration were nearly uniform. Fourteen species (66 per cent) were confined to a i single tow, with 17 at the surface, 8 at 50 meters, and 8 at I 100 meters. Development stages were again abundant at all three depths. STATION 6 May 31, 1928; 50° 22’ N, 13° 31’ W; bottom depth, 2604 m; 21 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 12.4 11.6 igs Density (ctp) 26.9 Dias 27.6 Salinity, 0/oo 35.5 Som. 35.5 Hydrogen-ion conc. (pH) 8.15 8.12 8.08 AcartiaiClausitigen si« «i /sesene toe 1s c r Oithonatseticeranmercr Hes see ee f a Calanus helgolandicus........... c SUT lish yer resets cues. sv ore aoe a a Cc Centropages furcatus............ F r r Oithoninajmanapee eee cee f ty PICUSH Serene tetez area b ster eratereoaet r ays Oncaeasminutamry-reeey ices f we Clausocalanus arcuicornis........ r f a VENUStaberper tert tscciniet ssc oe c f Macrosetella gracilis............. a ot r Paracalanus parvus............. <8 c r Mecynoceraiclausiens: ae eee r Bn Pseudocalanus minutus......... f Metridiatcurticaudas serene eee r r Rhincalanus cornutus........... c Microsetella norvegica........... c a a NASUEUS eeetenset swiss isis ces cave f TOSCAN: corsie{efeisscaysiaveies aoe eats aes r Sapphirinayangustas.-.--... +e r @Oithona plumitera:-............- Cc The temperature dropped only 1° in the 100 meters, the salinity remained exactly the same, and the hydrogen-ion concentration diminished very slightly. There were 14 species in the surface tow, 7 in the 50-meter tow, and 12 in the 100- meter tow. Thirteen of the species (62 per cent) were confined to a single depth and only 4 were found at all three depths. This is the only record of Centropages typicus for the entire cruise, a fact which, as this is a fairly common species, would seem to imply that it does not often come into the upper 100 meters. Here also is established one of the only two records for Metridia curticauda; the second record was made during the surface tow of July 11, between stations 6 and 7 (c). | LISTS OF SPECIES BY STATIONS 19 BETWEEN STATIONS 6 AND 7 (a) June 2, 1928; 49° 30’ N, 12° 00’ W; 22 species Tow 1 2 3 Tow 1 2 3 Bee AN GIAUISIN o step2 ccsterags or iene /o ct > a f a Oithonayplumuiteramee een r Calanus helgolandicus........... r r oe SELIBE Ira) crederayaie er ciwectoticuel sate le r fSandacia bispinosa............-- an Se r SIMILiShevees Hey oer c a a Centropages furcatus............ ae r om Oithoninaimanaeeeee eee ere Be: f r PERS: Ge oe HOB ee ool Oe r + r Oncaealimed iat eacas a. ern eee r Clausocalanus arcuicornis........ se oe r TILITLUtARyeeeea aes pelerccret erat f BS marranila carinata..-<..-..--% =< 1 is as wenusta a3 Sees eee aie r r f EOSULALA saree war hsteye cutie) aysveetts 3 oe as Paracalanus) panyuSs-seeere see a a Macrosetella gracilis............. r a r Pseudocalanus minutus......... f c c Senidialonga. on... veces. «coe as xs r Rhincalanus cornutus........... f Microsetella norvegica........... a r a NASUCUS ee eT eee f These three tows were taken at the surface in the same June 2. A total of 22 species was obtained from all three tows, locality successively at short intervals during the night of and 12 (55 per cent) of these were confined to a single tow. BETWEEN STATIONS 6 AND 7 (0) June 3, 1928; 50° 00’ N, 12° 30’ W; 15 species Depth of tow, m 0 100 Depth of tow, m 0 100 RANE TAMGIVUISLL tise) steve ys/a/atsietebarsicce wits sles = aes a Oncaea: medias = Ais ea oe eee f alanus helgolandicus...5.-.0:...2.02--5% r r UO Meats 8 Berne ented GA cin. o5 Suto c f 1] SSO AOS Fee eee ie f VEnUuStal. Bh. ositagin se cnn nes a f c Mircrosetella norvegica...:....:s.2es0c0e05- a a Paracalanusi paises jeer eee a a BeENOUALpUIMILeTAs no. os. ss aot hae se ees f Pontellaylobiancoisesss eee ee eee r RT lene te testers cers) fo/audisveie Sra arnciate r : Pseudocalantismminucus semen ienitt rts c SHEEN, eeyay che En caches AR ASER RO ae ORY CS: TIER TENE a c Sapphininarstellatanmrs serie certarcee rect ate r PRUOMONETAT Aer tras cctaie cae oi eie eke ns aie r f These two tows were taken in the night, and it is worthy of _ was also present at the surface. There were 6 other species at note that every one of the species found at the 100-meter level _ the surface that were not found in the 100-meter tow. 20 COPEPODS OF LAST CRUISE OF CARNEGIE BETWEEN STATIONS 6 AND 7 (c) A. July 8, 1928; 54° 33’ N, 6° 55’ E B. July 10, 1928; 58° 50’ N, 1° 48’ E C. July 11, 1928; 59° 21’ N, 1° 28’ E 12 species Location of tow A B (c Location of tow A B (S AcCarhiarclausiionre amrieiosmnccierion: a c @alanusiminonee yee cena ae f Centropages hamatus............ a f Clausocalanus arcuicornis........ f f Eucalanus elongatus............. f Labidocera wollastoni............ r The interval between June 8 and July 7 was spent in the harbors of Plymouth, England, and) Hamburg, Germany. Three surface tows were taken in the North Sea on three different nights as recorded above. Only 2 of the species were Metridia curticauda............ Microsetella norvegica.......... @ithonaspliumuferas...........--- Paracalanus panvlses.---o.0+ > +i Pseudocalanus minutus......... Temora longicornis............. a mmm Ss mp mp a taken in all three tows, but on the other hand only 4 species were confined to a single tow. The total of 12 species for three night tows is exceptionally small and indicates a restricted copepod plankton. STATION 7 July 13, 1928; 63° 20’ N, 9° 25’ W; bottom depth, 454 m; 11 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 8.9 8.2 8.1 Density (op) Die 3 Dil mii 27.9 Salinity, o/oo 35). 2 35.2 Some Hydrogen-ion conc. (pH) 8.08 8.03 8.04 Ncartiatclausitiyertaccy ssa -iyere c Qithoninatnanarmeseee ss - 3 - r GalanusifinmarchicuS-.-4. 4... a a Oncaea venusta yee ce atc.» +. r helgolandicussa....ssn965 a a c ParacalanusipanvuSaseeris. rst). Cc ie I Microsetella norvegica........... f r r Pseudocalanus minutus......... c f c Oxthonayplumiferac-e aes secs r c Temora longicornis............. a f f SIMMS ce aee ete poses tats renee b ieee sie ers c c f This station was just east of the southern coast of Iceland. The temperature at the surface was very low and fell less than a degree in the 100 meters; the salinity was exactly the same at all three depths, and the hydrogen-ion concentration varied extremely little. The bottom depth is next to the smallest for the entire cruise. Only 3 of the species were confined to a single tow, and 6 were found in all three tows. This is the farthest north for Oncaea during the entire cruise, and this species may well have been brought into this vicinity by one of the ramifications of the Gulf Stream. LISTS OF SPECIES BY STATIONS 21 STATION 8 July 15, 1928; 63° 30’ N, 14° 41’ W; bottom depth, 1308 m; 12 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 10.3 9.0 8.4 Density (orp) 27.0 Dilla 27.9 Salinity, o/oo 5,2) Boe BS) Hydrogen-ion conc. (pH) 7.93 7.95 7.95 BPeATULANGI AUIS crete cs jenee) 41™ p.M. to 12'50™ a.m. At stations 8 to 13 neither Corycaeus, Farranula, nor Oncaea was present; all three were found in this tow, and the two latter genera were taken also at station 14, and all of them later. This latitude may therefore be taken as approximately the northern limit for these genera. Sration 14 August 9, 1928; 42° 10’ N, 47° 19’ W; bottom depth, 4154 m; 32 species Depth of tow, m 0 50 100 Temperature, °C yhtenl 14.9 14.0 Salinity, 0/oo 352 Som S48) Acartiallongiremiiss cs sse-- + « r Aetideustanmatuse -ja.).0 62 el ne f Calanus' finmarchicus............ G LOREM GHENSS acanugoanentes ie Se YALA OL crave fe Speceasteusue can coteatone peters f c Galocalanusipavor 4-5 sees r r Styliremisy qcccyects cis. sscsue aoe «6 if Gandaciainonvegicae- acs ae r as Centropages furcatus............ c hamatuss armen seme Creme ne ae M3 r VAGEYCEN Chon epeoenn ese bres r f f Clausocalanus arcuicornis........ a c c Eucalanus elongatus............. iG r Buchirellasbrevisis sci cm cele iecrsies r r Harranulaxcarinatay. eye ciel ee iF ROSE LA alae cis eye eleva ede Pie cyeusiens f This station, with the two which immediately follow, is in the Gulf Stream, which was here crossed by the Carnegie nearly at right angles. Consequently the surface temperature was high, but fell 33 per cent in the upper 100 meters; the salinity and hydrogen-ion concentration, however, were prac- tically constant at all three depths. In spite of the warmer surface temperature, only 5 species appeared in the surface 0 24.6 8.18 50 100 Dilek 8.06 Depth of tow, m Density (ot) Hydrogen-ion conc. (pH) Haloptilus longicornis Mecynocera clausi Microcalanus pusillus Microsetella norvegica Neocalanus gracilis tenuicornis Qi Paracalanus parvus Pseudocalanus minutus Rhincalanus cornutus MASUCUS)s. .- eerie SPIDINOSELISs sya eee a: a Oithoninalnanaeeeeeeeeter ere S< a Oncaeaumintitareeer eee Similish, rae yenseeteces er vorreerec: f a tenel lary yvetreryete in are Berar VENUS Ae crcsain «cr Meera artes a Paracalanus panvllssaseneeine aaels Te ok Pontellina plumata............. Pseudocalanus minutus......... Scolecithrixdanaeee ee ener r Undinulalvulgarise-pecie- eee Peni et ee mF ist ts} tall tavetsy He 2-4 >a! 4 The temperature was high at the surface but dropped 2° at 50 meters and 9° at 100 meters; the salinity and hydrogen- ion concentration were high, with little variation at the three depths. Fourteen species were found at the surface, 23 in the 50-meter tow, and 21 in the 100-meter tow. Sixteen (47 per cent) were confined to a single tow and only 6 were present in all tows. The small species of Corycaeus, Farranula, and Oncaea were abundant in the surface tow, but Oithona was absent. LISTS OF SPECIES BY STATIONS 31 STATION 23 August 29, 1928; 10° 50’ N, 37° 24’ W; bottom depth, 4787 m; 60 species Depth of tow, m 0 50 Density (o¢p) Hydrogen-ion conc. (pH) Depth of tow, m 0 50 100 Temperature, °C Pipe 20.9 16.5 Salinity, o/oo 35.9 36.0 36.0 Acartianlongiremiss scje= «ses s00 34. c Calanus helgolandicus........... a c ANIIT OL ere eave eked =) eneyveunse ais tere c c (CalocalanusspavO)n seis syete se e-seveve- r Candacia aethiopica............. ae r IS PInOSalerrerctoe eieraie ro eele sie a r ts fall Gikeraer ren teier ee ay seere ctasercae : : 29 SUMP ERs eters cusses dos: cuensancesoocie f f f NAGIGAMIS mart chen cgencyaayerch ose ct erences f Centraugaptilus rattrayi......... ae r Centropages furcatus............ f GCopiliaydenticulatal<.. 5)... 4. - r (ony. Caeus ACIS «scien cee acne ete «ie f ee GhASSINISCONUSH sete ererers creisiereie ee c c c DWE UIS Pye terctareee socks oi svecsasarsvaysee 4 a NN sola bode doen Cote f f SPEGIOSUSM seve tevevecyersey at pr The temperature, high at the surface, dropped about 6° at a depth of 50 meters and an additional 4°4 at 100 meters. The number of species is increased to 60, 34 of which were found at the surface, 30 in the 50-meter tow, and 30 in the 100- meter tow. Thirty-five (58 per cent) were confined to a single depth and 9 were found at all three depths. Species of Cory- caeus and Oncaea were again especially abundant at the surface, and this tow contained one of the two Atlantic records of Pontellopsis regalis; the other was made at station 24 below; the species is rare at both stations. In the 100-meter tow we find the only record of Centraugaptilus rattrayi and of Candacia falcifera for the cruise. 32 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 24 August 31, 1928; 8° 15’ N, 36° 10’ W; bottom depth, 3836 m; 50 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C Dill 2} Al 155 Density (otp) 22.8 24.9 26.8 Salinity, o/oo 352 36.0 35.6 Hydrogen-ion conc. (pH) 8.32 8.14 7.96 ANcantiavlonginemSme cir ct sci ae c a Heterorhabdus papilliger........ G Aetideus:armatus’ ...:......--.- r Pucientialclaviswitr starts es se a Calanus helgolandicus........... c a c HAaVvAGORMISPee neni seer ox Cc S0UPLXG) Ge CHE MOS CRO CRITE a ORO a c Macrosetella gracilis............ c f (e PLOPINGUUS seis ee gooonn a a fe Mecynocera clausi............. f ads Galocalamusypavor je ereclecisiee> f Megacalanus longicornis........ a f styliremis)... 52sec sein aes cis r Microcalanus pusillus........... f c Candacia bispinosa.............. a c PYSMAEUS A cyae enselseoke eave f MOLVEPICA TS Aaet qor.eceisiers ie a Microsetella norvegica.......... os f c pachy dachylaresteriienisrtr eri: f f Miracralettcratann amen s a r 2} 600) 9) (SS coke CRO O Or n OS COT { Oithonatsinnlisheewmerer errr: ys f c VELOC Saree co coors oon One Be f f SPIMIROSULISE aptente neers or f f Centropages furcatus......:..... r ae r Oithoninainanal sa. seer el 50 { at Clytemnestra scutellata.......... f r @ncaearmeclianwe erence terete ete f Corycaeus crassiusculus.......... f oe MINUtals,.octas woe moe eee ne Vi a SPECIOSUSH ss dace no ae cee f f f MOO Pally, «,2ys.5,brersseyeterersayekeveare r EY PICUS cyatenchsiens siete yeferess sev eheys f ar VenUstalteac nse ceratectiecisc c if a Eucalanus elongatus............. c f ParacalanusspanvuSerntiiiel tel: c uchaetalmnarinalsaevarierteve ante ces: a c Pareuchaeta grandiremis........ r BuchirellaibreviSeac tec. e c iG Phaennaspimiterary...rreel rir 8 f r Rarranulaicaninatalnvei-y. eal) a a Pontellopsis regalis............. r ks Salo ENS Ab Gomomauneocen soaen c Pseudocalanus minutus......... Ets c c TOSthata.;.cys~ cree sera syn swiss ce a5 Se f Rhincalanus cornutus..........- G Haloptilus longicornis............ aA oy c Scolecithrixedanae se err ernt Be a c OFNACUS hrs = ae otis csisiefls ss = Ae c Windinulakynleaniseee terete aa a r The temperature here dropped 4° in 50 meters from a high value at the surface, and 8° more at the 100-meter level. Fourteen species were found at the surface, 30 in the 50-meter tow, and 36 in the 100-meter tow. Twenty-three species (46 per cent) were confined to a single depth and only 4 were present in all three tows. In contrast with the preceding records, Corycaeus and Oncaea are each represented by a single _ species in the surface tow, but the former is better represented in the 50-meter tow and the latter becomes very abundant in the 100-meter tow. This last tow also contains the only record of Pareuchaeta grandiremis and one of two Atlantic records of Microcalanus pygmaeus. LISTS OF SPECIES BY STATIONS 22 STATION 25 September 3, 1928; 11° 02’ N, 37° 06’ W; bottom depth, 4851 m; 31 species Depth of tow, m 0 100 Depth of tow, m 0 100 Temperature, °C 27.4 14.6 Density (orp) 23.0 27.0 Salinity, o/oo 35-9 D5 (/ Hydrogen-ion concentration (pH) 8.31 7.93 ENGATMIAWLOMPIL ENNIS sere ya) sadn eeavel sie (ie eree ches ts a Megacalanus longicornis................. a c fealanusrhelgolandicus..j0.0.s2.-+-s00.+-- c c Microcalanusspusillitsaeprer see ieee tte a f NNO) Sach ob DO CT eOIaLiG BOR Ge Ox Roe carota c PYEIMAGUSAN A ara opts cava qupereys te r felocalanus;paVvOne.c sce ce ss sec se se f Miraciatetterataanmc cite tar oer cts eitteeeie c SUVlILEMUSee Ema esck code win eee eine r @ithonayplumiferapeerere yee ar f imeiica Clan DIS PIN OSA evectas cst we eecielous sees ove r G SEMUILISE tv eegee err test cee isiank evel rte es r VEEN vloo oucls dduaecps aadea wanes SPINITOStHIS Pane ae acre Sristeeoiee erecta at r ORCAS BRIS ash sees oon Gblees toe aera ee c Oncaea mediate depesteeiet tervernsrn sya eyes f GrASSIUSCULUS Hee cccjave siete ous Seiars Fctaysie sos a ATLUM UGA cess ee at easter hater eee a ita DNS od croo. eee Geom bee or See f NG CUES soe aia den 4 Os Ee eno. os GO 0S Cibin a SDECIOSUS Cai ter iy sy er-iteiorisie ase sie acronis ae a Paracalanusipanvuseemetn emcees a f BG ha eta TATA. serie spss ei a, 2 ceases ee cad os oe c Bontellimayplumataseenee reser crane rr f BeimanWlaGatinatar as cues cries ete cess ee a Bontellopsis perspicaxe erie te siete r LiGicninn GEIGHS 5 ou dco dase ness neadaenadn “fs f Pseudocalanussminutusiys cmc erties a> Be c Macrosetella gracilis... 2. c2sc cece cee es ss f Temoraystyliteramn vec ae Moree ocuetreste a f MEG YMOCELA CLAUS. :s.-fecciei« ck seinem cise ai ae r The high surface temperature dropped almost 50 per cent at a depth of 100 meters, but the salinity remained practically the same and the hydrogen-ion concentration dropped 0.4 of a point. Sixteen species were found at the surface and 19 at the 100-meter level, and only 4 species were present in both tows. The 100-meter tow contains the second Atlantic record of Microcalanus pygmaeus, the two thus occurring at adjacent stations. STATION 26 September 5, 1928; 11° 33’ N, 40° 43’ W; bottom depth, 4492 m; 6 species SN OcCAlANUS PAVO!K... ose. ecg ees © c Corycaeus speciosus Corycaeus crassiusculus........... f Farranula carinata. . f Macrosetella gracilis...........:.. c Oncaeaeventistalmm cree cers f Towing was done at the surface only, with temperature 27°6, salinity 36 o/oo, and hydrogen-ion concentration 8.30. Owing to very bad conditions, heavy tide rips, strong cross- currents, and a rolling sea, the two deeper tows had to be omitted. This is a smaller record than that for station 10, but this is one tow only, taken under very adverse conditions, whereas at station 10 all three tows were taken under good conditions. 34 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 27 September 7, 1928; 11° 20’ N, 44° 12’ W; bottom depth, 2571 m; 41 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C Zits 26.0 od Density (orp) 235 24.2 26.5 Salinity, 0/00 36.2 36.2 36.0 Hydrogen-ion conc. (pH) 8.31 8.30 8.09 Acartia longiremisse es. o-)1- lo - a f Macrosetella gracilis............ c c a Calanopia americana............ ie Se Mecynocera clausi............. r r Calanus helgolandicus........... c a f Megacalanus longicornis........ f r IMMATLO Tyee eres ra ae earch, aie) estate f a Microcalanus pusillus........... f HS Calocalanusipaworern ltrs f f Microsetella norvegica.......... f c a GandactaybispinoOsay en). ciel -te f Miractaetteradtale.1y cr ove -r Sears a6 r WSucicntialclausie, sn «clemson 3 Macrosetella gracilis............. f f c Depth of tow, m 0 50 100 Density (otp) 23.4 23.8 255 Hydrogen-ion conc. (pH) 8.31 8.29 8.21 Macrosetella oculata............ ip Mecynocera clausi............. r Megacalanus longicornis........ 3 f r Microcalanus pusillus........... r r Microsetella norvegica.......... f c f LOSCAMP ITM. e eee ayos 3 ees c Miractayefferataw-yte.cc scm <= < E Oithonaisinnlistaercee «co: 6-1 c c SPINITOSELIShe sean] oss eee oe be f f QOneaealcurtateerecnc.:ese. sc. f THC GIA BWA ens eosin sors f MUIMUbA ewes: seesciae ae ss : ib c NGUURIE: 56 ocho mB AO ONO DE OO f c Paracalanusiparnvusee is - <7 o- c ae f Ehaennayspaterdse rnin. ci. Ri ie Rhincalanus cornutus........... = oh r Scolecithrix danae,............. FO f f Undinulavulganisteee ee... -- =< a f f The drop from a high surface temperature was less than 0°5 at 50 meters and 4° at 100 meters; the salinity and hydro- gen-ion concentration were again practically unchanged and quite high. Twelve species were found at the surface, 23 at 50 meters, and 26 at 100 meters. Seventeen species (46 per cent) were confined to a single depth and only 4 were present at all three depths. The 50-meter tow furnished the only Atlantic record for Haloptilus spiniceps, and most of the Corycaeus species were conspicuous for their absence. Two species of Farranula, two of Oncaea, and Corycaeus crassiusculus were confined to the surface tow, and neither species of Oithona appeared there at all. LISTS OF SPECIES BY STATIONS 37 STATION 30 September 15, 1928; 12° 54’ N, 56° 15’ W; bottom depth, 4703 m; 48 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 28.0 ist 24.1 Density (op) PP) 235) 25a Salinity, o/oo 36.0 36.0 36.3 Hydrogen-ion conc. (pH) 8.30 8.30 8.26 Calanus helgolandicus........... c f c Macrosetella gracilis............ c f c ATLIMOW. faye) = ote he spss siay sasha enet ays yee f c (YNENE Fb oooabooojmerco don r at PLOPUMAG UU S ape pe steye = eheisi nfevaecete f Mecynocera clausi............. ae f r alocalanusipavOs... 2.5 .+-s-.- a ic f Microcalanus pusillus........... j : r GivnlinaraiGhs ao guobomvcmouee sc f r Microsetella norvegica.......... c f c Candacia bispinosa.............. f ROSCA hey vances parce evciere r c pachydactylan 335 yose a. 2-15 r Oithonaghebesmrrer teers eter : r SIM Plexeyetree toss see sig cscs eee 2 ix an f plumiferats ace <-> ee ae f Centropages furcatus............ 50 r Similisy vce cut svecchers swecerons = ay c Clytemnestra scutellata.......... oe r SPINIOSbIASiys toe se eee c Gonycacusiagilis\.<: eo. os ne en ss 2 r Oncaearcuntamem eee aeeer r GRASSINSCULUS em es sive ee a TEM ars et ene Ae vsccparsye Fears eran f in iniSerm steed ert ahs r THIMULA she wionis 2 © onlcrs see eset f f VEO VERTS Re. a oo Salsa ee eee, ep te : r NOLOPayasiee eae ne ie r Himba busts secre ecigiesrs +) econ r SUD tiLiS aya ees rece tows es ceaa act f F PUMIUS ae slew wae es ee ses 44 ae r fenellar tye os sere co teaietsus one bi at r SDEGIOSUS Metis atic eh sere Hare a f 2 VENUStA st. eee aptrerh vial’ a Buchaetalmarninay. of -. r f Clausocalanus arcuicornis........ f f Clytemnestra scutellata.......... r r @opiliardenticulatapenem seen r @orycaeusranglicushres iene. r =: GlAUSIT sitar = cuts wena. Sse r GraSSiUSGUlUSw ae sere = sel a HACCUS! cc stn: Qecemeaecae sts r ITLIMULIIUS ey eieeieys Fete tevetee ene he : is r SPECIOSUS, farisk eeientras err Gr 6 f c ESV DICUS eyeeenegetste curse arstaiee ie eres f 5 Puchaetarmanindaern cee reas c f Harranulaicarinatalys serene eens c c Cuntae Sy eee estee wees eh r at a Pibbulaiscacrwes sas ose spictass ce at: f MONE ooo agoouonDoDASaAoO sie a c HMaloptilis onnatus. ea eeeeeee f Depth of tow, m 0 50 100 Density (orp) DA Hydrogen-ion conc. (pH) 8.27 albidocerapmentinn. ta. el-\-r0- =i = r Lubbockia squillimana.......... ie r Lucicutia flavicornis............ (eo Pa aXGl har & 3 01k aoe eee Macrosetella gracilis............ at c Mecynocerajclausin.....s..---5 Microcalanus pusillus.......... si r Microsetella norvegica.......... A c @ithonayplumiferas .. 4.4... ..---6 i f SCLIQEIA oe. cine icie soe cea me r SiS. 5 vos ee SOR een Oro SUMLROSUMISeisysy- seca eee Oxthonimainanaeeeeer ace eee Oncaeaiminutar.. 2-2... - sence (REGIE. 5 Sots Doe e VEGI. Ano HOMES Oe as f RaracalanusiparvilSe....).-. eee. a Phaenna spinifera.............. Pontellinatplumatan.). 14-4 Pseudocalanus minutus......... Rhincalanus cornutus........... ACU Ny, oo ign oleae Bea eee a6 Sapphirina auronitens.......... Scolecithrixidanae. .......2- ane ihemoravsny literal. 140-0 s.r Ly Po ake Pole) =z Wiha jth hah (ol sree ad mp BR) Ft (oe eh eS ama Dp mmoat mp fp !: for) torbt a} lene 2y Ia2y © A high surface temperature, with 5° drop in 100 meters; a low surface salinity, rising 2 points in 100 meters. Nine species only were found at the surface, 34 at 50 meters, and 38 at 100 meters. Twenty-seven species (52 per cent) were each confined to a single tow and only 4 were present in all three tows. The 100-meter tow contained the only record for Lucicutia grandis and the 50-meter tow one of two Atlantic records for Corycaeus claust. The small species of Corycaeus, Farranula, Oithona, and Oncaea were especially abundant in the two deeper tows. Again none of the 4 Oithona species, only 1 of the 4 Farranula species, and 1 of the 3 Oncaea species appeared at the surface. LISTS OF SPECIES BY STATIONS 39 STATION 32 October 5, 1928; 15° 18’ N, 68° 11’ W; bottom depth, 4566 m; 54 species Depth of tow, m 0 50 100 Temperature, °C 28.0 PM? DPR?) Salinity, 0/oo 35.9 35.9 30-8) Acanrtiavlongiremis. 1k see an 28 c ANetiGeUSiaLMabUSs. a6 «ise ciere oe a, r Calanopia americana............ ts a r Gllipticasepyet- citi cet ceok erie r sh Calanus helgolandicus........... c TNO toycodec on pooner coe f a f PLOPINGUUSHereree cero: r CalocalamusipaviOr a am «ete ; r (Candaciaybispinosay meme -cieae ae r r MOGVERICAayeyyelarsre eteVsvel<%- sion r ine ; pachy dactylalrcss tects ce cine = Yo r r Centropages furcatus............ f ds r ve eVGUS ome stonctey ieee teysietee errs eens Clausocalanus arcuicornis........ r sis Clytemnestra scutellata.......... a0 r @opiliadenticulata:..-.-:.-.:-=- r Gorycaeusranglicus:...--.054---> f GhASSIUSGCUMMIS Hee eiter te eeie eel Br eA f GliinWeygooscoud oad cootenae r HUTRCTIS Pete oa eee aerobics Sereroae r NAUUGUS MepeeRferesc.stcic eens steer sors 2 TIUUMUUTAL UL S eae tyovar stores eeekeuererers) 0) Sons 5 es r SPEGCIOSUS ter ejetepevsasicueleiece ctetere i=) f a a Eucalanus elongatus............. Ss c f uchaetabmanine yi - c a Mucicutia havicornis....s.0..-s6¢ c Spinocalanus abyssalis.......... : : r Macrosetella gracilis............. r c f Temora longicornis............. i r ie OCULa tar pe aus: stir ssh ala ls wher pis r r styliferass Spe antemetae accor c r r Mecynocera clausi.............. f if Undinulakvulganicaec. seer Se c ic The temperature, high at the surface, dropped 4° at 50 meters and 4° more at 100 meters; the salinity increased and the hydrogen-ion concentration diminished downward, each by small amounts. Sixteen species were found at the surface, 40 at 50 meters, and 35 at 100 meters. Eleven species were found at all three depths, and 16 (33 per cent) were each present in but one tow. The surface tow contained the only Atlantic record of Pontella securifer and the 50-meter tow the only Atlantic record of Sapphirina scarlata. All the species of Corycaeus, Farranula, and Oncaea were well represented at the surface, but only one of the three Ozthona species appeared there. 42 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 35 October 26, 1928; 6° 32’ N, 80° 04’ W; bottom depth, 3583 m; 96 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 27.4 16.8 14.4 Density (orp) 18.6 25.6 26.5 Salinity, o/oo 2907 34.7 34.9 Hydrogen-ion conc. (pH) 8.31 7.92 7.88 Volume of tow, cm# 80 112 96 Length of tow, miles 0.7 0.8 0.8 Scartia canaries ibis Es 2 4 Haloptilus spiniceps..... M8 ON 3.8.5 2 NAWMYONG odongoanacoo5 75000 = 2 Heterorhabdus papilliger........ 4 3 Acrocalanusieib bet... +. i ten 4 a : Heterostylites longicornis....... oe 1 GPSS s coos g adn anoonseoowGD { f f leubbockiaaculeata)...° 2... sey a c loneicounismeree ister r f ie Squillimmanaye severe 3 Aegisthus spinulosus............- c Linsrouine: CEMSHE a enuoeodononoe 5 f Netidens anmabus series ter ster HY: 4 f Hey IGORMIS Mrs cise eae eee r f Amallothrixarcuatasy..o6 se.) re 39 Macrosetella gracilis............ 2 Augaptilus longicaudatus......... or 19 GCUEE. 5 55 podeeeImase donc 1 a Galanusiminonesseee ere cca f f iF Mecynocera clausi............. c f G@alocalanuisipavOreseerteitel teen f 2 1 Microcalanus pusillus........... 2 c c plumulosuseeterrr eee 2 a DIMAS, couopasounoeoned f c Candacial bispinosas eee 3% 1 Microsetella rosea.............- 2 f c Simplexe-e nes eee eters 1 1 1 Neocalanus gracilis............. f r UUMNCMEY «cc anmeagoooouound ea 1 3 AOU n oo PERO EOROn DOOD 1 Canthocalanus pauper.........-.- 2 4 4 Oithona attenuata.............. 3 Centropages calaninus........... 1 a 1 MAACOMNS. oso pnpanpeoonoc 2 Clausocalanus arcuicornis........ f f f SHS. oo oo DSUE eRe toner ot f c flurcatilispemeraera ricerca. 1 SoionrOewiliasaooebdsouoboc f c Clytemnestra rostrata........... 2 ai @ithonitmasnanarrrrs 4 cere see = 2 @onaeararact lishment tet: f 2 Oncaeavanelicadesssci nlc fe 29 at GonycaensianeliCuser y-)-rr ly ael= 2 COmleraepets ccd eceveccieuosis sis 2 r GME. oon cosanadua nooo moton 4 CWT. 550050000 De SUED OD oO r a c GSS MECMMWSs c555 a0 0ag00000K r CUAGIZs oo aon da OMS De r FEVCIBso0 codeonDadnoboneada r f MECHAM rer eekeie: chieyssieicheuss a a a eres tole CliG Lemans retelebeieiieretre ier 6m HOO) oto 7 a Ome ee O10 a a a PAUIEUS!S 26) ae octtcss ate ess azote verses 2 3 ShaeelSs 0.4 co. cee OM eae cee f f c HimalbatGuse sy. cicero clserxe oe teh: r r 1 SUDEINS eeIae caies) oe « osere cre 2 ite fits OGKAL a ee) serecs = sreietss aera Me 2 EMIS talenyenetsre = re-2, s.siciei sere aes f a a DACIGUS Atri metr deters 2 * ParacalanusipanvuS. -\.)-. - te c f c jue ICs 5 Aoionanas OOOBONGO 2 f Ty PUMA CUS eet aay. ptt -r-) 2) eae 36 2 * SrA Saccocesasiundgesssere ore 2 Phaennalspinitera....-....-..-) 4 r Eucalanus attenuatus............ f f Pleuromamma abdominalis...... 2 ClONPACUSH Mee rier teraersiatr- 3 f (FRAO nin o-nlcene REE arose r MADMAN, sogogccboaoodume 3 f Pontellinayplumata......-..-.5- ie 2 MUCLONACUS.) 4 2) ee D. Pseudocalanus minutus......... f c ByiGhaetale GUta rea tetertrereriereiars 4 Rhincalanus cornutus........... Pe oar f ebesreps cca. cohen ol ues io lere 3 TASES emer nero eyesore reneher tte me 1 MATMMTB. > sag acne Hobodon Do oF f f Sapphirina auronitens.......... 5 Buchirellatrostratal. 0-4 or an 1 MS HOM GUA EA eli lt) yee 1 BaGrauula carina atameenee tet y te a 5 r Scolecithricella abyssalis........ r GOS. enonosanccr aon bone C 4 f lO, Sow os NOD OOOO ES oc 1 3 GUIn baie ti erat niereemine oe cacrot rons ott 2 Scolecithrix danae.............. 1 3 Pale om avedode pens omen eb 1 1 3 Menmloranciscaudatal. «- <1. cabins 5 ROStrata decree hore ots ve a ma LOWPIGORDIS] i. skits eters 3 (CAgemicgeinwSrosesenasopcests 1 Temoropia mayumbaensis....... De bg 3 Haloptilus acutifrons............ 4 Undinula darwinii.............. ae or 1 lonPiCOnuIS ete tere 5 Vettoria granulosa............. 5 f This is the first station in the Pacific Ocean after passing through the Panama Canal, and also the first of a long series of stations, 35 to 80, all of which are considerably influenced by the complicated network of surface currents that prevail in this part of the Pacific. The stations from 35 to 42 are in that part of the Counter Equatorial Current which turns south on nearing the west coast of Costa Rica and crosses the equator, swinging back to the west and joining the soda LISTS OF SPECIES BY STATIONS Southern Equatorial Current (map 2). Under the influence of this current the surface waters of the region maintain a high temperature and a low salinity, with the hydrogen-ion con- centration slightly alkaline. That these conditions are favor- able to the copepods is seen in the exceptionally large number of species found at these stations (see p. 5). At station 35 there were 35 species in the surface tow, 58 in the 50-meter tow, and 71 in the 100-meter tow. Forty-seven species (49 per cent) were each confined to a single depth and 19 were present at all three depths, an exceptionally large number. If the designations of relative abundance in this station record are examined, it will be found that half of them are numerals, which indicates that although the three tows yielded a large number of species, at least half of them were represented by 43 very few individuals. Again we find the smaller species the more numerous, those of Corycaeus, Farranula, Oithona, Oncaea, and Paracalanus totaling 31 species, nearly all of which are well represented. The 100-meter tow contains the only record of Euchaeta hebes and Amallothrix arcuata, and this and the 50-meter tow contain the only record of Conaea gracilis. The Temoropia species was described by T. Scott (1894, p. 79) from the Gulf of Guinea and reported by A. Scott (1909, p. 119) from several localities in the Pacific considerably farther west than the present station; it was also taken by the Carnegie at station 152. The scarcity of the Candacia species is also worthy of note, since five of the six records consisted of single specimens and the sixth record was of only 3 specimens. BETWEEN STATIONS 35 AND 36 (a) October 26, 1928; 6° 16’ N, 80° 17’ W; 65 species BNGAT lay GANAC). 2.05, soo Coal NAO Fe mrNH mE! mwWPp Pp : OLN AVGU Siena ce oes spars es comes ws ar 1d MMCHUE, soondgaednocobeces ofr = Heterorhabdus papilliger........ 4: bes 1 Labidocera detruncata.......... c Rubbockiayaculeatas:. 2... 4). “0 ir f ILpcneminn GWE. oongneeeonDe ds MawAGORNISHa. cops coun ai 4 Macrosetella gracilis............ 4 Microcalanus pusillus........... aie POV MAC US peat. ens farsse ase cere f Microsetella rosea.............. 2 Neocalanus gracilis............. 1 KIMUICOMNS. sodcucussa5coUe Qithonavattenuatay............- plumniferatyeecs sic): scsi 6 ecuets Sols, ofan 0 Some aes c SpINITOStiaSeyreratea messes eee Oncaeavanglicagas scie- 62s Be a 19 Cunvataeerestetry ris esces eo to RDm™weePnHm: = I INSITE se trie > Pp pp Bp: Pseudocalanus minutus......... Rhincalanus cornutus........... MACDUUES cons Tesus cb ao BOA Sapphirina auronitens.......... 4 Scolecithricella bradyi.......... et 1 Scolecithnmadanaeaeem ni: rs shemora discaudatamer: eye -) sce sty literate arc ctescusiers esate Whachinnls, Carob, s.sceeaes98en es Gannwilnniimererrsta sie) c's) ss 3 oie Ne - f VU LCG SRP Ree ers cic) sie ste ssf oueke ae) rs) al » Qo 2) 3 (= n uo) o is} < i=] n (e) Oma mp Wem bp 4 Forty-four species were present at the surface, 37 in the 50- meter tow, and 49 in the 100-meter tow. The surface tow of 0.5 mile yielded more than six times the volume of plankton that was obtained in the 100-meter tow of 0.8 mile, but the latter contained 5 more copepod species than the former. The three tows totaled 75 species, of which 38 (51 per cent) were each confined to a single depth, and 15 were found at all three depths. LISTS OF SPECIES BY STATIONS 47 STATION 37 November 1, 1928; 5° 59’ N, 82° 56’ W; bottom depth, 3324 m; 88 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C Dien 19.8 Sie Density (orp) 20.2 24.7 26.3 Salinity, o/oo 31.6 34.5 34.9 Hydrogen-ion conc. (pH) 8.28 8.00 7.82 Volume of tow, cm* 224 32 64 Length of tow, miles 0.8 1.0 1.0 BNC ARUIAC CANA osc ee cose Cieicie nvernie ci 2 3 Labidocera detruncata.......... a MaG ccod poco OOo oO Eo te f 2 Lubbocktaracnleatarrr-t-i-rt fe + f Acrocalanus gibber.............. f Squulllimanaaneytcraeiaereia te au 1 PUA CUIAS Ss heat steretels. © e7sih Suenos ors @ f f MuGicutiaybiconmutarya- niet oe 1 is OWACORNE sao aoe ooeoeseon f 1 GENIC amaaee gelded concn bles oe 1 f BetGeus aLMatUS. «cs 4.0 or 4 flaviGOnniseen rire ee f CITE Trt OR bcs geompomO need c c c Mecynocera clausi............. 1 r ealocalanus pavo: = .6<<2 2.05: c f Microcalanus pusillus........... f f andacia bispinosa....-.....-.-- 2 PYLMACUS Heyy etayke ae cette G f f machydacty lacs . .06 sar a f a Memorardiscaudatae..-.--.--- = f 2 GUECA Sin a cece cs. acae eis serdians Pe 2 2 Undinulavcarolineeren et =<). r gibbplaerncacer. oe acer eet a f c Gan wintiereescec ais «ct aves, a 3 f racist Nscters we rncl cee caseys ss 3 VU TALIS Meer ite ss cobs. esc eneys 4 ie f Haloptilus longicornis............ ad 1 Vettoria granulosa............. 4 The drop in temperature here was 40 per cent, the rise in salinity 2 points, and the rise in density 5 points. The 50- meter tow, with a length three times that of the surface tow, had a volume only one-half larger, and yielded half as many more species. The 100-meter tow had twice the volume of the 50-meter tow, with the same length, and yielded almost twice as many species. There were 25 species at the surface, 40 in the 50-meter tow, and 72 in the 100-meter tow. Forty-six species (53 per cent) were each confined to a single tow and 11 were present in all three tows. The 1 Aetideus and 2 Euaetideus species were restricted to the 100-meter tow; the 3 Candacia species, 4 of the 5 Eucalanus species, the 4 Oithona species, and the 2 Rhincalanus species appeared only in the two deeper tows. Corycaeus and Oncaea were well represented with species which were divided among all three tows. One specimen of the new genus Danodes was taken at the surface. LISTS OF SPECIES BY STATIONS 49 STATION 39 November 6, 1928; 0° 52’ N, 81° 14’ W; bottom depth, 3200 m; 85 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 24.8 16.3 14.0 Density (op) 21.8 25.6 26.6 Salinity, o/oo 32.9 34.6 34.9 Hydrogen-ion conc. (pH) 8.24 Loo, 7.88 Volume of tow, cm’ 336 48 38 Length of tow, miles foil il al oil mcartia negligens...............- he a f Heterorhabdus papilliger........ 2 merocalanus) gibber..:....0.0..-5 > r x r SobbiMsneroosememogoococ 1 re LACS setae cis erivehs aie le 5 f ws 3 Eucicutiaiclaustiesscne acs ee 1 NOMA CH US eens sets,cqetn mssjerest, s1cis's 1 se aa flaVICOGUISW erry re eee eee is 3 c Aegisthus spinulosus............. un 1 3 longicornisin-jce soe emee Hee 2 Wetideus armatus............... f Macrosetella gracilis............ ae i 1 Amallothrix obtusifrons.......... 2 Microcalanus pusillus........... f f c alae avie soc oobenuodouoe OG a c DYRMACUS Eee f f f Selocalanus) pave... a= <1... 5 << f c Microsetella rosea.............. 2 r feandacia bispinosa..........-..- ais 1 Mita claseheratarenn stern terre 4 r aa QUEM ssdbdcbouvesdcs0bocne 2 Neocalanus gracilis............. 2 4 paGhy act ylais ess). os r Pseudocalanus minutus........... r EY PICUSS sepie Aon rere ere r Miraciavefferatamemer ce eee. 2 Undinuladarwintt. 9-2. - 5422s 2 EncalanusiGrassuseee eee oer 2 INeocalantis:gractlicurervetiias a. here r vulgaris. 3.0 .5i2% 006 sss f Barranwlaigibbulayaqec-eaniee alr 1 This nocturnal surface tow was less productive than those meter tow at station 42. Two of the Corycaeus species, agilis between stations 35 and 36, and yielded only 19 species, half and fypicus, were confined to the deeper tows at stations 41 of which were represented by 3 specimens or less. Calanus and 42, and catus did not appear at either of those stations; propinquus was not present at station 41 and only in the 100- nor did Miracia efferata and Undinula vulgaris. STATION 42 November 13, 1928; 1° 32’ S, 93° 10’ W; bottom depth, 3539 m; 74 species Depth of tow, m . 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 18.7 a2 13.8 Density (ctp) 24.8 25.6 26.7 Salinity, 0/00 34.7 34.9 35.0 Hydrogen-ion conc. (pH) 8.06 7.99 7.92 Volume of tow, cm’ 32 134 64 Length of tow, miles 0.7 0.3 0.5 NcarbianGanae cers seus cu-sase cia erate 2. c i Heterostylites longicornis....... r ip MENG wap ae comune on dood an 3 Ke Lubbockia squillimana.......... ay f 5 Acrocalanus'gracilist 2.4. .4. 2-7 r = Be BucicutiarGlausiiomye cin. « ek oe aS 3 f Aetideus armatus............... Se 2 f BENVICONSc. c.o6 HOO Oe O at f Arietellus setosus...............- 3 ig f Macrosetella oculata............ 1 Augaptilus longicaudatus......... to pe 19 Mecynocera clausi............. 1 ae (@alamuis minor yee cielo «9 oie were = ae f ie Microcalanus pygmaeus......... 2 1 PLOPINGUUS seme si sree ee i: 2 Microsetella rosea.............. r c r Calocalamus)pavOr. om. site a i 3 Neocalanus gracilis............. 4 r Staylinemisis,- ces crsmcge ae - oe r ict KODUSHOLMee eee. se os eis 1 Canthocalanus pauper........... f 2 Oithonarattenuatar.,....--.---5- Be Ir au Centropages calaninus........... 1 plumiterareierlics shee cere ar 2 HU CA CLS tert exci Geyer che ener 1 Thi (Sa. co u.6.0 WAC E eS c a a Clausocalanus arcuicornis........ a0 r a SDIMIROSELISMEIe = eienint = <1<1s cious 2 c jAUIREN AUS. oo Sekoeciaiche GoGo OF 1 ai = @ithoniuamnanamee it... -1< 1 3 (Gonycacdsvapilisteri.- h-picsroisrere = a a (Oncacarconileramerrs seis cs «<1 f a CLASSIUSGUIMS mance = lero c Gini, oncpe oodpadoepepesan f r AuUbIUS teers ietscs esse shete oe evict f CUInVataMppeaereists. ss 'srsie guste over r r hill Ceasod Hoomece se toca f HAChEs 6.5 6.5. 2 OCI c a PMNS eres aeeiens ernie cise renee 1 a6 ne TLE UL CA Meme Me per freaayio1e + ep seb ecane c a a SPEGIOSUS mane cee ease tee es iG r ae SHS s o oars AON OROMaGnoT o 2 r 150f DLC chenctockeraI aie OG OOo c Si f a SHO GUS Hprpneper- kath =e eyetote r a6 Danodes plumata, n. gen. and n. sp. 29 oe a WEEE.» . Soca OER oie Co i r Eucalanus attenuatus............ r VEIIUIGUAMEIENS Grails «enn vray s@.erhae a c GRASSUS oa veieece: sucks cryscr ates cee = ; r Paracalanus aculeatus.......... 1 elongatuse assem cer sen cect. oe f f (BEING. 0 dhe: Gaktoe ceils © a a a AMOMA CH USE ele eishs sey) sveesysve orate oh f f Phaenna spinifera.............. PA 2 uchaeta acutaese-ice- asetecele ene ae = 3 Pleuromamma gracilis. ......... e 3.0 f NILATANL AS s-yoraysve, Mesewere pacar ccc 2 4 r Pseudocalanus minutus. ........ f c c Harranulaycuntavn .ficlsctelrrarcstests 1 r Rhincalanus nasutus............ f c gibbulain ain2.eee0-5 seems 2 f a Sapphirina auronitens.......... 1 PRAGUUISBieis sseusi oie aes) esses seehener=) f a a Scolecithricella bradyi.......... 1 LOStratatrestes « cai dee oly scerae"s c ak Scolecithrix danae.............. r Haloptilus longicornis............ 1 Spinocalanus abyssalis.......... 3 3 PIWIMOSUS eee ter= yrs cher s crakeyera tease 1 (Udiamlancaroliicn.. ss-jcis acne 1 SPINICEPS4y aes aes ete ee 1 Gin (itt aan mmdeee dec 56 r Heterorhabdus papilliger......... f WVettoriareranulosa. ....6.0...--- 2 LISTS OF SPECIES BY STATIONS 53 The temperature fell 5° in the 100 meters; the salinity and hydrogen-ion concentration changed very little. The 50-meter tow was four times the volume of the surface tow although less than half as long, and it was twice the volume of the 100- meter tow, but only three-fifths as long. Hence, as would be expected, the species were erratically distributed at the three depths, 19 at the surface, 50 at 50 meters, and 44 at 100 meters. Forty-three species (60 per cent) were each confined to a single depth and 7 were found at all three depths. e) Corycaeus, Eucalanus, and Oncaea were again well represented in species, especially in the two deeper tows, but Candacia was entirely absent. The 100-meter tow has the only record for Arietellus setosus and one of the few for Augaptilus longt- caudatus. Haloptilus, Heterorhabdus, and Heterostylites were confined to the 100-meter tow. Although Paracalanus parvus was recorded as abundant at all three depths, the actual number of specimens was much larger in the 50-meter tow than in either of the others. STATION 43 November 15, 1928; 2° 30’ S, 95° 43’ W; bottom depth, 3352 m; 71 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, ° 19.5 17.0 13.5 Density (otp) 24.7 Det 26.7 Salinity, o/oo 34.8 34.9 35.0 Hydrogen-ion conc. (pH) 8.09 7.93 7.90 Volume of tow, cm? 176 32 32 Length of tow, miles 1.8 2) 12) AGRE: GENEGS Fanon aodondddouds c Megacalanus longicornis........ ae 1 MOGI SENS aera ctelvoicrencvese cosier=he! a 2 Microcalanus pygmaeus......... 4 3 Wcrocalanus gibber.........-..... c r a Microsetella rosea.............. r f PRAGUIS Ay spore craic ci Seca sleeneer oes r f Neocalanus gracilis............. f 2 HIERN TAN) ase 56 cs eee oer enrES c c RODUSEIORS serer-pa tite cee ke f 4 PAGOPUT GUS ere pyre srcistic oy eieus elt sols ab 1 (NOURI TNS onanoeoonounsos awe 19 Canthocalanus pauper........... lof Oithonalattenuatameey seer ee r Centropages violaceus........... 1 uss plumiuferay sericea cect je r Clausocalanus arcuicornis........ a f f Similis eyes «fo sets cemeteries a a a AWE ODL EIS ar iether cxphb Cb meee Pee ONES c f GoM HIS. ooononscancacoos ; r f Bonycaeus agilisn: nw es ene f a c Oithoninalmananecmee dace oe Ais 4 PAMGKE WSI's che cycjens) saieceisus sna at a a @ncaealiconitenabeeer aera “ 1 Cablismra rockin asnytudaaete ge actu oe 42 1 CUEEAR sh pouatetoracieusn secs. c steers f f f GMESUSCUINSs oso ocaceeneoaee f TEC aba nye neers fey oe coos aa ete c f c GUC USepyaryatattsstctais esses ens « 2 mediterranea,............. r r Ae HAC GUSH see weeeic rey. denser ote aus: « f WINUtA Sees aaGoweiae oe veers © a a a SMECIOSUSretepersteleyeccnsilay sco cutie. ++ 3 _ NOCOPAyz faeee wisteceres scietovayss f see HSV UGUS meteters eueyclais face o.stas aie s r r 1 Simtlistepietnes senha. ePee ae a f Danodes plumata, n. gen. and n. sp. yee) on SUbtilismaeters svat f f f Eucalanus attenuatus............ r tenella pence Sc Soereit ess avers e555 f f GRBs copaeccusuncnao gone r as VWEIMONE oo co mocoundoon ooo Cc a a elongatuse aa qepetec.cs at cer r 2 Paracalanus parvilse-..ce-- - + a c c LOIN GIUUS tere weadte ste ao suis enei fis c c DYE MACUS HME verte ete eens ae as 3 MAMNCHOTEN Ban og ooo aaaneeude r Phaennarspiniterasetareeen el at 4 ns CMOWETENS: oc orton conto aoe eee id ah Pleuromamma gracilis.......... su ee 19 Brichaetay aGutay. ake see sei e ee es = 3 f Pontellaidandeseasesrereeccreran: f # Be THEN OUTENG. 6 cig. Gob kD GOD Cee 2 f f Pontellina plumata............. f Se 1 Bichirellajpulchray.....----.-- <1 3: 1d Pontellopsis regalis............. f Be Harranula gibbula..............-. 2 Pseudocalanus minutus......... a f c PRACNNES oe 3.5 cac-6.o ee r 2 2 Sapphirina auronitens.......... ae r r OS tN CA eR Tosh ALI cary aio cnn eee" 2 Mignomaculaital ys). sarc yi 4 Haloptilus longicornis............ a ae 1 Scolecithricella bradyi.......... f 1 Labidocera detruncata........... f Spinocalanus abyssalis.......... f 1 Lubbockia squillimana........... oe a 1 Windintlarcarol near perceeec ric f oe Mucicutia Clauses ....22-2 21.26 3 1 danwinueeaemeeen ener e f f Mecynocera clausi...........--- r The temperature fell 6° in the 100 meters; the salinity and hydrogen-ion concentration changed but little. The surface tow was 50 per cent longer than either of the others and its volume was five times as great. Twenty-five species were taken at the surface, 53 in the 50-meter tow, and 44 in the 100- meter tow. Almost exactly half the species were each confined to a single level, and 14 were present at all three levels. Corycaeus, Eucalanus, and Oncaea were more numerous in . species and more abundant in individuals than at the preced- ing station. The two former were especially evident in the 50-meter tow, the latter in all three tows. Paracalanus was much less abundant than at station 42, especially in the two deeper tows. Two specimens of the new genus Danodes were taken in the surface tow, but it is apparently nowhere abun- dant. Of the 25 species taken at the surface, those of Clauso- calanus, Paracalanus, and Pseudocalanus were abundant. 54 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 44 November 17, 1928; 3° 15’ S, 99° 48’ W; bottom depth, 3423 m; 89 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 20.6 20.4 Tia 7/ Density (orp) 24.4 24.7 26.7 Salinity, 0/00 34.8 34.8 35.0 Hydrogen-ion conc. (pH) 8.03 8.04 7.86 Volume of tow, cm’ 246 80 192 Length of tow, miles iss} ile) 1S Acartiaudanaererrcterstcretrereretereeles (o c a Heterorhabdus papilliger........ ee 2 Tor piremitsite. evecsyeisuetateve oe shores 1 SPIMNLKONSh 6 «iss < sysersereleeecs oe ac 1 Meg gense yer ec see tacts ce c f 2 Heterostylites longicornis....... ee As 1 Acrocalanusigraciisn sitter f f ie Labidocera detruncata.......... f Aetideus armatus............... ote oy c TCL eed et tes stays os. 2 see eres f Amallothrix obtusifrons.......... Lubbockia squillimana.......... as r 3 Galanusimimonseeeer eee ener eri Bt c c ILS CMA. GENENE Saamooboauosco 1 ee 3 WOE Oe od wom aD R Asoc a ae 2 Macrosetella gracilis............ r te @alocalanus pavore- cee eee eee 1 f ig OGilatate never. csc eves arsrsre sors 2 SbylinemiS=-rremiers crests a f Mecynocera clausi........-..-- 2 (Ganda Giavanila tale serstensietererseteteetare 1 Microcalanus pygmaeus......... f f rhc (Ca aes ane OMG meee Gree 0 OT 1 Microsetella rosea............-- f c Sik plextor y vast sieteton sictapstop: Neocalanus gracilis............. f f GEUMCACA Garr wien ol erslclenelo 3/ a r ben LODUSHORMee yea): lacie aa f Centropages calaninus........... 1 EENUICONNISMes seas = che ose 1 ete Clausocalanus arcuicornis........ c c QOithonatattenuatay.--..-.-.- 1 f f AURGAEWS rsteecevesarsievversureestc/essiais c ae f plumiferaiye . .-.: «nee nse ts ac r oa Copilia denticulata.............. oe 2 1d Shin lie ona ccc COR eon c a c Conycaeustagilise=s: 7a f ce f SPINIGOSEGISe ere eo eis 6. olsen f c a ANGE WSIly se ipeices. nce ss-0s Gi ueastec f c c @ncaealconiferagae sa. <-5< f GCAbUSH sere meenere ccciemieeaet cits varnees f a i (ll betielicsn Gro o, 5 cree Eon ER RRR Te f f { CLASSIUSCUIUS ss aera ete ee 1 r 3 TCC almeponetsneieye(etekens sre. scutes c f c BEYECWSs:s Haare b6 Hid bIOED OAR f ANIM Care eveelereb res 2:6 te a AUMATAITIMLS eeepc tenet se yetetctertcnere 2 ete 1 a8 TIOLO Dalene chee wie este wie shane r PAGCIEGUS He cyevenie eee ratene crete rohereys : r S(mmiliSmegmeretetre te overs os azaleas an rE f PUTTS Mater; sectors us cusictoryscebers f r Sli. s oc cdpnooeReadtoron if SPECIOSUS Sade ania tieraees ere 2 2 WEEE! coconvo oo pepiEeeee 38 a a SVL LI Semarea stage spoke toteeme tere sensiines c r RaracalantsmparuitSmeei ici «1c a c c Danodes plumata, n. gen. and n. sp. 49 Phaenna spinifera.............. se c Eucalanus attenuatus............ ae 1 Pontellaydanaene.s-. 4-15-)- = 32- 1 CRASSUS eel alas ostor tes tse tens ae ahs r (HENRI Rer eA occ ae aN Aeon c LON gallus agers eet ersten onto oe f f Pontellina plumata............. r MONA GHUS sete es es eke. csereleesreeeree ne c r Pontellopsis regalis............. 2 ae TAUCK OUAGUS wre = -cvers one) senses ie oa f Pseudocalanus minutus......... f ti c eichaetatactltaey.rcts citer -t-yerrlerehece's a te 3 Sapphirina opalina............. ey se 1 iin Wee Sain SOOM O MOOR Ono xd f r Scolecithricella bradyi.......... 3 ReimearE) Clint coca cacas ones aos r 5.0 MAT giMNataee ryt <1 = = sl 4 Sib b ula sats dette) aceereiore r c Scolecithnisadanade ese e212 1 2 Graci lish: pete cysayact ce aerate a f Spinocalanus abyssalis.......... ae eS 1 GOSULAULA ya yayen sues lee) cucttKea®) hers chets a r Memoralshyliteraertrrs--\ --- = -1-- 1 Gaidius tenuispinus............. 56 1 ae UindinulatcaroliGmrimre. o-oo. 6-1 ee a Haloptilus acutifrons............ 1 GEicitatles coe Cee enereeS oe a r longi COnniSprrt at. annals te vee | Vill SATIS Mera ele «foc + s.ccesiete Fe a PlUMOS See oped se arersre etic. 2 Vettoria granulosa............. 55 Ks r SpInicepss semolauitse ase 1 The temperature dropped only 0°2 in the upper 50 meters, but fell nearly 7° in the next 50 meters. The salinity and hydrogen-ion concentration were fairly high and changed very little. All three tows were of the same length, but the volume of the surface tow was three times that of the 50-meter tow and 1.3 times that of the 100-meter tow. Forty-nine species (55 per cent) were each confined to a single depth and 13 were present at all three depths. Thirty-nine species were found at the surface, 53 in the 50-meter tow, and 50 in the 100- meter tow. Corycaews and Oncaea were rich in species, which were well distributed in all three tows. Eucalanus and Oithona had 4 or 5 species each, and all but 2 Oithona species were confined to the deeper tows. The 4 species of Haloptilus appeared only in the 100-meter tow, together with Aetideus, Heterorhabdus spinifrons, and Spinocalanus. The surface tow contained Corycaeus minimus and Labidocera nerii, which were found in only a few other localities. The 3 species of Undinula were abundant; 2 occurred only in the 50-meter tow. LISTS OF SPECIES BY STATIONS 55 STATION 45 November 19, 1928; 4° 35’ S, 105° 03’ W; bottom depth, 3342 m; 66 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 22.4 22.4 18.6 Density (tp) 24.1 24.3 24.8 Salinity, 0/00 353 35533 35.4 Hydrogen-ion conc. (pH) 8.12 8.13 8.11 Volume of tow, cm® 118 80 118 Length of tow, miles 28 5) 2.5 “COE GENEOSS 6 pemoteooedcouod ae a a Labidocera detruncata.......... f Be MAANINIgA Sy CaO DS SCO MeeanEO f f f Mucicutiayclantstlepertetrerteterersretets 1 Acrocalanus gracilis............- 2 r 2 favicornisaacciecm cesar 1 MOM ATIUS TINOL sees -)- 66 selec eis = = = : f Macrosetella gracilis............ Fe 1 3 fealocalanus pavo.«.-.5....-.-+- 2 f f oculatating, ane cierichremecr 2 Siwliewss sacuopsesousodowe os r Mecynocera clausi............. f a 1 Candacia pachydactyla.......... oo 1¢ Microcalanus pygmaeus......... be 1 1 STIN PLEX acy ac) cies cya! creve ere. tvs- 21s Microsetella rosea..........-... se 1 a Clausocalanus arcuicornis........ r f Neocalanus gracilis............. 5 HNKCTLAUES sits Sea poen aeto om Aare a A f DODUSELORS ,5.sysnsre axe co eherereie, ote : 19 Clytemnestra rostrata........... Bs 1 Oithona attenuata.............. c f { Morycaeus agilis.........22...2.5.: r DreviGOrnis!. < 6s 2 ccrsv<.>.3) nes ae 3 2 GAGS cae Sys yayerets, o.<.2etese wpe the.s ae f 4 plumiferamectanocere oR e see 3 Gra SSIUSCUIUSH ery yet ae ie r f 2 Similistren eye ieee poser c a ‘at Gh SUES eo Sets Os SOOO Soe 2 bi SPINITOStLiS ss saan cess ws ee ous an r { MnambatUs' cee... seeps «overseers scsusce r r @ncaealconiferaseecra-tsses: 75 1 POUMUUS Soot sisi. o ere «isis ces 4 CUTbAYs esate gies bie Serets e siars es f GODUSEUS ters arecae sen eels 2 it TEC 1AS ce peso reg Vente coda eu EES f c a SPECIOSUS. miysbteele eo eastng aire ot r f Sr SaMbhoUNtacsy. clare ctoictarg GeOeig actor c a c USONCUGoas:2.o meno aeree de Germters 1 ae il MOCO PAL. eravsnsse steve eachs See ors 3 3 | Eucalanus attenuatus............ iF bi Similis aes soon e 6 aatews ie a elongatuSaccieasccec es eee: = f f Sloss apace os ape to ovOr r MOH AGCI US itheye ey sauce telsse esse eueens c f tenel aan sae sce mcrcnsyo seats te r CHSCs Geese aoe meen 3 ae NOMA. coocaceboo0mIDGedE c a Buchaeta mMarina...:..>........-. 1 Paracalanus parvus............. a f Euterpina acutifrons............. ae 2 1 Pontellatprincepsa-sesemce eae es 1 hah | DIRE COIs one ciaiee coco f a 3 Pontellina plumata:....°-...5.. 1 1 RELL cteee yepeccie eucrete anes wesc c f Pseudocalanus minutus......... c f RAG Senior cuchefercen «a6 eZ Ae Rhincalanus cornutus........... ae a c ROGAN pono Son enhooeOneee a c ie Scolecithrix danae.............. a 1 Haloptilus acutifrons............ as Be 19 Memoraystyliferase, sees eee 2 Heterorhabdus papilliger......... Ee oe 3 Undinulaicarolitaaey-ts caer Heterostylites longicornis........ te 2: ld Garwinits< 2 af atserersescarereye oye ie 5% f There was no change in temperature in the upper 50 meters, and only a 4° drop in the next 50 meters. The volumes of the surface and 100-meter tows were one-half larger than that of the 50-meter tow. Again just half of the species (50 per cent) were each confined to a single level; 11 were present at all three levels. The vertical distribution was 31 species at the surface, 33 at 50 meters, and 47 at 100 meters. This is the first appearance of Pontella princeps, which was found at a few of these eastern Pacific stations and nowhere else. Corycaeus, Farranula, Oithona, and Oncaea were each repre- sented by many species, well scattered through all three tows. Candacia, Eucalanus, Haloptilus, Heterorhabdus, Lucicutia, and Rhincalanus were each confined to the deeper tows and did not appear at the surface. The 100-meter tow showed an exceptionally high percentage of Oncaea and contained both species of Acartia. 56 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 46 November 21, 1928; 9° 06’ S, 108° 20’ W; bottom depth, 2905 m; 57 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 23.3 23a), 2255 Density (orp) 24.1 24.3 24.8 Salinity, 0/oo S548) 35.3 35.4 Hydrogen-ion conc. (pH) 8.16 8.16 8.17 Volume of tow, cm? 128 64 32 Length of tow, miles 1.8 1.8 1.8 Acantiandanaes eiasascesteyatrersesiee f a Haloptilus longicornis........... ae ato 5 MEP PENS Arete wren ee rei een c r Labidocera detruncata.......... c 1 oe Ncrocalanusieracilisia asi. aes 4 r r WGuGicttianclausiieje. «sc rele ees f AILOMA GU Sep vensyessue ic ecegeys psietec & HAVICOGIISE. ciac a sae cle ates 3 Galanus minoues-ieierrce tect : ae r Macrosetella gracilis............ 2 r r Galocalanns) pavon a -seeses cre aie 2 2 an OCW acaepe rie chcteusss) sisi evens 1 Gandactarsintplexee eres ect ais f r Mecynocera clausi............- ae f r Centropages calaninus........... 3 Microcalanus pygmaeus......... 3 OEIC Gon anomaoe doe ope on 19 Microsetella rosea.............. we f f Clausocalanus furcatus........... 2 c Neocalanuseracilisn. misc. - 6. Ss f Clytemnestra scutellata.......... 1 Oithonarattentatareers qe 2 c G Corycaeus andrewsi............. 1 plumuferammerierciiissiis ce a= ae 2 r CALUS Me ete ss, sores seietese Gees ie 3 Similise Beep as ysis eee S c a Crassimsculusy. sancti 3 f f SPIMITOSENIS wertenie ses eis ass > 1 f iEKS OD Signe o chee FOr Recerca 1 @ncaeayconiferaver cm ecce nos 2 Himlbatuserc-ccresee cen canes 3 f f ALECIAN me efene ued enssrtveue-s,, sus csrece c c OEY ITS chavs GRR Metrics CRG e Cane 2 4 AULUMLUCAE cn ct teers se se sess a c PaAGthCUS) 4g) havc ese yeieeeetsrcustens 2 ae HOO) Oy oo. go Ro ooh AO OE EK 2 5.6 PUTS are eens eee r f 3 SUIT (lish reece isis eves r LODUSEUSiarencie ier eracr ee ae 2 ae ar UGE 53 Sab oS eb Eee 4 SPE GLOSUS yap: teu cq c segsveassoooispnere oe ie f METUStAcy Metre ice ccs vis r LS TOC C GME cicie bee cretees AIO c 1 4 G Paracalanus)panyuSee--- ec: «-- = c c Eucalanus monachus............ r rc Pontellavatlanticaeyee ese... +. -- r Buterpinaracutitrons sees 1 4 Ss DELUGE PS ye letieramins cies s cs c Harrantilaycaninatarer soars a ic a Pseudocalanus gracilis.......... 29 GUGba a neyo oie ents ee eect Ab f c MTLINUCUSPRE eee te ricls ok » acs. fe f c pibbulatem eric os, tees centaur a f f Rhincalanus cornutus........... STACI Seiden Watcha ia dee c c - Undinulaidarwintiteencs +... -c.- 6 c f OSI oo onog OmeeITG COE OO ODE a a a There was less than 1° of difference in temperature through- out the upper 100 meters, and practically no difference in salinity and hydrogen-ion concentration. The three tows were also of exactly the same length, yet the surface tow had twice the volume of the 50-meter tow and four times the volume of the 100-meter tow. Twenty-two species (40 per cent) each were confined to a single level and 11 were present at all three levels. In vertical distribution, 20 species were found at the surface, 39 at the 50-meter level, and 44 at the 100-meter — level. Corycaeus and Oncaea continued to be represented b many species, but Candacia and Eucalanus were each reduced to a single species. Curiously enough, whereas the Corycaeus species were as well distributed through all three tows as — before, not a specimen of any Oncaea species appeared at the surface, and only 1 of the 4 species of Oithona. The surface tow contains the only record for Pseudocalanus gracilis. LISTS OF SPECIES BY STATIONS 57 STATION 47 November 23, 1928; 14° 07’ S, 111° 50’ W; bottom depth, 3080 m; 53 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 23.8 23.8 PDA Density (op) 24.4 24.7 25.3 Salinity, o/oo 35.9 35.9 36.1 Hydrogen-ion conc. (pH) 8.23 8.23 8.23 Volume of tow, cm* 144 38 32 Length of tow, miles eal Wet ited BAG AGEIAG OANA Cia. 5 ie ieee ls iee wiele ese ane ea c Haloptilus longicornis........... eA f a | MERI PENS agar eis svarray« yee «ks r 3 Labidocera detruncata.......... a Acrocalanus gracilis............. r oH = Mecynocera clausi............. bi c r sealocalanus pavo.....-..2..s.s+ r f 1 Microcalanus pygmaeus......... 3 PUUUIMUIOSUS A pests vim cess ars 1 Microsetella norvegica.......... aes ilies. Spo hon peed dao : r GOSEAs 4 5 saci cteoe sient esi eee trois e f f f eandacia simplex...........5..-- 3 r Neocalanus gracilis............. Pe c Centropages calaninus........... 1 Ojthonavattenuatasece meee c c r Clausocalanus arcuicornis........ f Similisiices sercceversaresisropee teres a a AUT GAGS ete ratees re oreo} se aserencitsreycuntc a 2 SDININOSELIS MEE eater a f Clytemnestra scutellata.......... 2 Oncdealcurtaee assert eeeereeier f a Morycaeus. agilis....0.5..505.065% 2 MUNULA Ney rracierssece : a a HA CCU Suricesscetsssuatsne soos Sa agecause 1 MOCOPAtMatepececcnwar tare Nee Be ce 2 DALIEUS Meg tersr oie ass 5 dds vrais 1 SIMIIS,. may coemr meee Ose x at r MAD LLUS Geers ic cyeie is. atk eres siaceaden f f 1 teéniel lays rage ette eteecani ee as ee xo 2 NOM PAS tay IS)rcrese ee ieeteycs s:sieleeSieis 2 1 Paracalanus parvus............. a f f PURE IS EM eeree tas oe f 2 Labidocera detruncata.......... a 1 4 ING ROE TOS Paes 5 5 5Qo0000000 ie = f eucicutiaxclausit ..-1\-)-\5e1r~ are f (Calbia mititoyr; 55 cononcancponens 30 f ae Hla VAC ORMIS Tete sist sore.) @ncaeakeuntalerer nie cue se ee ere UIE o.oo a nop SO Ao mm eeeeG NOLO PAMmed wee tiowi Aw eaves Sim] ispyepeeeaeecrs see cts cee ace ous mht tn eh ee we p p : et VENUSta sepa seh ns als aves ParacalanusspanyuSa.-- 5 6-5 <= - ac f Pleuromamma abdominalis...... gracilisyaenyasrersc ser sc siete =e 1 Pontella tenuiremis............. a Pontellina plumata............. Pseudocalanus minutus......... f Sapphirina auronitens.......... 1 Opalinaeamemerete. «= «% cyte Spinocalanus abyssalis.......... Windinulascdarwantteerres 11> r co oO i=) oO = i TOG mW aa ww = OW 7 Wo? ence for one depth over the other. The 6 species of Oncaea with one exception were confined to the 100-meter tow, and the 6 species of Corycaeus and the 4 species of Farranula were well distributed in all three tows. Although all 3 species of Oithona were found to be abundant in the 50-meter tow, it is to be noted that not a single specimen was found at the surface. LISTS OF SPECIES BY STATIONS 65 STATION 53 December 5, 1928; 29° 06’ S, 108° 44’ W; bottom depth, 2871 m; 66 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 2255 2 19.9 Density (ctp) 24.6 Dae, Df] Salinity, o/oo 35.7 35.7 35.6 Hydrogen-ion conc. (pH) 8.22 8.20 8.20 Volume of tow, cm’ 48 32 48 Length of tow, miles ils7/ 2.0 250) Acrocalanus gracilis............. 2 r f Macrosetella gracilis............ BC 2 AN Augaptilus longicaudatus......... 19 Mecynocera clausi............. f _DIGCAEME CEM Ome ooacn Sono onan ae 2 f Metridia brevicauda............ r feandacia bispinosa............<:- aa ae 4 Microcalanus pusillus........... 4 Tia Os. comes acosanteanee mi 3 r PY PIMACUS py tye tater vartetctakets f (HRUMNCAIA = Sas aadoeponoddatnon ; ae 1 Microsetella rosea.............. ip Centropages calaninus........... 1 2 Miractalefferatase-.-- oe nacrdas sh Clausocalanus arcuicornis........ 1 f as Neocalanus gracilis............. a f c HURGACUS tere eieteerisisier ctu =s 3 ap ahs 3 FODUStIOR. 215< ge does ee : f opilia denticulata.............. oe i Oithona attenuata.............. ws f AIA DIM Aecrsicaerse sso 1s 3 similissMoncrease oer etc oY. ae a MonyCacus Cats... oie dee ens wee. a 1 Spininostrism-ycrcry-t- el -e1 1 f GCLASSIUSCUILISm tines secs oeickel= a 4 r Oithonina nanap eres eee ae 1 ate MACCUS cetecet eye ferte erie sicte W avencis 2 Oncaea curtakinc o- ce cme ls sar 3 WANTNEUS prewertsas an sis eacicyess sist f f YALUML UL CA esfatts soars eevee (aust sucvs'ors sev an c c Pm babs ices ceo. -actectarems avere ie 3 NOLOpameereens meter eee cs Sas r r MON GISEYLISH ucts seas sas eyes 5 tenella te temeerrt sentra : r FRUITS er cats ois «soleus 3 =e 3 Onchocalanus nudipes, n. sp... .. 1 ENT DIGU Sire eessstasetsveracs a3) <8 Geo Ss ats f c Pachos punctatum, juv.......... 19 Euaetideus giesbrechti........... 2 Paracalanusspannuse- reer 2 if c Bichaetar acuta... 20. «. vas ss fs 1 5G Pleuromamma abdominalis...... : UME TUTI cee cress caste recat cteraks eA r r CT AGUS Ee recess rarar earns & f f Bruachirella pulchra.........<.0+%.- 1 Fontellajprincepss-ee-ecte= «eee MAT Way CAriMatalarcscists< 1 Onchocalanus nudipes, n. sp... . . 19 IMAGINE ice srccavcteysais heise 3 1 Paracalanus aculeatus.......... a a 1 uchirella) brevis....-...+--.-.--- 4 [DENG So 6.5 ee cee OEE r c c Farmamulhl Gases 554560 e0eBeoe f (e PY GMACUSH cle oes cloaiee sre. elenet s acs ae r CONC Es CEB oR eie na eeeices r Pleuromamma gracilis.......... F a a SUI GTe 2. plots 6 OOS Onn meer c f f Pontella tenuiremis............. TA CHIIS epee ttegareneesye eh sve ech aie 015% 1 r f Pseudocalanus minutus. ........ f c f OSHA CM eer Seeieni ake = cess c c c Sapphirina auronitens.......... 2 1a Haloptilus longicornis............ a MisrOmaci lata wemers sees e 2 Heterorhabdus papilliger......... f Opallinalarescrrtris.c fos ede os 2 at SMITLOUS HEA a mtd scualeeiec. 5 f Undeuchaeta plumosa.......... 1 mubbockia aculeata............-- BS: 1 r Uindintulavcanolitemerccccs. ees r SOME El o56 saoedoaonoees r GET. 5 sane gaa eee r a Wettoriaverantlosae ss... .... + 1 Linge) GEMS 66 pon5 Se Aes The temperature was fairly high at the surface, and dropped nearly 4° at 50 meters and another degree at 100 meters. The salinity and hydrogen-ion concentration remained very nearly the same at all three depths. Fourteen species were taken in the surface tow, 40 in the 50-meter tow, and 66 in the 100- meter tow. Forty-nine species (61 per cent) were each con- fined to a single tow and 9 were found in all three tows. Though the surface tow was less than half the length of the other two, its volume was the same, but was evidently not due to the copepods it contained. The great difference in the number of species in the three tows suggests a strong light for some time previous to the towing, and this assumption is reasonable considering that the station is in latitude 29° south and was occupied in the middle of summer. This is one of two records for Lucicutia curta, 2 specimens being found in the surface tow. The 8 species of Corycaeus, 5 of Oithona, and 8 of Oncaea were entirely confined to the two deeper tows, except a solitary specimen of Corycaeus catus taken at the surface. One specimen of the new Onchocalanus was captured in the surface tow. Candacia, Euchaeta, Haloptilus, Hetero- rhabdus, Lucicutia, and Undeuchaeta were all confined to the 100-meter tow, except Lucicutia curta. 68 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 55 December 16, 1928; 32° 03’ S, 110° 55’ W; bottom depth, 2725 m; 82 species Depth of tow, m 0 50 100 Temperature, °C 20.3 18.7 16.7 Salinity, 0/oo 34.9 335150) 34.8 Volume of tow, cm* 32 64 96 Acantiaimeslivensarn. sacle ees 1 1 Acrocalanus gibber............-. : PTACIIS Se crete ote spoke cise yee r f Aetideus'armatus. ¢. 2:5 ..0..0. 5: Galocalanusipavon-neeeeerer rice a 3 DIUM OSUSHe ase eee se 2 Abies vodoadannansancos es ie 1 Candaciaybipimnatay) .-eeeeeers ys eS 1 DISPID OSA eps erepae petites aie erate longimanae cee sacrament aE 3 PLOVER GA fy 5, ects. -ntustewercierareats ons = 1 SUIMPLORGN ae eters a twoyetegsinreevs. aSy2 sé 4 r EGUIM CALA ecto nctey cr o-esohetone ua corerer bs i 1 Canthocalanus pauper........... ae 3 Centropages hamatus............ 1 Clausocalanus arcuicornis........ 2 AI KCATUS ae ener etuelcne erento Gopilaydenticulatamea- etre 33 4 quadratialesrerces errors ace rere fai WAG CA set tcmer gers sree. tay Conycaeustcats meee at eter re + r Gra SSilisCulusmeeer saree ree Ha CCUSH sas eer ache tise crt ar ENR one ee Eis. omni ae ae r Minbar US tore ce eseiste eis wisueis-s ae f lon gishylisme cs suaciye rie abel creer: PUES er w oma cccrece deve okesie mics 3 BODUSEUS a avareuscareerciare sterteun c NEMA cro noob oo000u0K8KC a a POLGOILUS fee spetege exes teyerne steps ats f r Paracalanus aculeatus.......... 2 r (SONOS, ore eae oo Acc eee c c PATVUSiy nay. care shee Me epiee aia c a Eiicalanlis!Grassus. ..\.. 9226 < «2 aA f r Scolecithrix danae.............. ES a a Neocalanus\ gracilis: 2222-50: -- we Li c Wndinulardanwinit.; .< sc o.--eee to 2 4 This station was next to the farthest south in the Pacific and hence showed a low surface temperature, with a fall of 5° in 100 meters. The salinity and hydrogen-ion concentration were moderate and changed very little. Five species were found at the surface, 15 in the 50-meter tow, and 21 in the 100-meter tow. Eleven species (46 per cent) were each con- fined to a single tow and 4 were found at all three depths. Although the surface tow was shorter than the other two, its volume was three or four times as great. Again this was due — to the large number of ctenophores it contained, which helps to explain the small number of surface copepods and the still further drop in the total number of copepod species. Scolect- — thrix and the 2 species of Clausocalanus composed a very large percentage of the 50-meter tow. LISTS OF SPECIES BY STATIONS 73 STATION 60 December 26, 1928; 40° 24’ S, 97° 33’ W; bottom depth, 4007 m; 12 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 14.9 13.4 10.6 Density (o¢p) Zoid 25k) 26.5 Salinity, o/oo 33.9 34.0 33.9 Hydrogen-ion conc. (pH) 8.07 8.06 8.03 Volume of tow, cm’ 64 36 36 Length of tow, miles 0.3 0.6 0.6 Clausocalanus arcuicornis........ c r 3 Oncacaimedianneeeeee erect: 1 RU CALLIS Mr eeyeeictere siase)eyeief tora) c ie Paracalanusiparyuiseeeerry sil a r 2 Miecynocenauclausiene Meer. seer a c ANAS. ossadocuauuesene c r Microsetella rosea............... D, 4 Pseudocalanus minutus......... a r Mithonay breviconMs. ..2..-..-+.- c f Scolecithnixadanadesesncrree eerie an a 1 SLUMS stayerorese eye or eraeese veka say a a Wndinulatdanwintiteem secre Bs 1 This station was the farthest south for the entire cruise and had a low surface temperature with a drop of 4° in the upper 100 meters; the salinity and hydrogen-ion concen- tration were moderate and constant. This is one of the lowest totals of species for stations in the Pacific, with 5 species at the surface, 9 in the 50-meter tow, and 9 in the 100-meter tow. Four species only were each confined to a single tow and 3 were present in all three tows. The length of the surface tow was only half that of the other two tows, but its volume was nearly twice as great. Though the ctenophores were con- siderably reduced in number, they still made up the bulk of the surface tow. Parucalanus and Pseudocalanus were excep- tionally abundant at the surface, Mecynocera and Oithona similis in the 50-meter tow, the latter in the 100-meter tow. Corycaeus was absent from this station and the following one, but reappeared between stations 61 and 62, and 5 species were present at the latter station. The fortieth parallel is probably a little too far south for this genus. BETWEEN STATIONS 60 AND 61 A. December 26, 1928, 4 50™ to 5® 50™ p.m.; 40° 26’ S, 97° 12’ W B. December 26, 1928, 7 50™ to 10" 20™ p.m.; 40° 22’ S, 97° 02’ W C. December 26, 1928, 10" 25™ p.m. to 1 a.m.; 40° 22’ S, 96° 59’ W These three surface tows were taken the same night but a few miles apart. The first tow, from 5" to 6" in the late after- noon, yielded 7 species; the second tow, from 8" to 10 in the evening, yielded only 2 species; and the third tow, over mid- night, yielded 15 species. It is also worthy of note that the third tow, although shorter than the second, yielded a volume eight times as large, and this volume was four and a half times that of the first tow, although the latter was twice as long. That the midnight tow should contain twice as many species as either of the others is, however, exactly what would be expected as a result of nocturnal migration. The species found in it that were not present in the other tows 16 species Location of tow A B € Location of tow A B ( Volume of tow, cm? 64 36 288 Length of tow, miles 3.0 1.8 1.6 Acrocalanus gracilis. ...... 0... r Oncaeatcunvatales saecscs 2 )steere= f BeallamlisitONSUS ayer «seis sseisekis cas ae f f SUTmiListwaeeaetotees fatsie: 6. soeteyets f Clausocalanus arcuicornis........ f ParacalanitsapanvuSree wile se ell c c WERROZI AI Doel 5 so olaeeuaeed noe ee c f Pleuromamma gracilis.......... r Microsetella rosea.............-. iF Pseudocalanus minutus......... c c sNeocalanus gracilis.............. r Scolecithnitxadanaecsaener ers f Withona brevicornis............- a f r Undeuchaeta major............ 1 Ship, ag oboe Goo ON AS f c Undinulatdarwinttiens os a0.- «> «1 r are the ones that require a longer time to reach the surface. This may be due to slower progress or to a longer distance traversed, Undeuchaeta probably coming under the latter al- ternative, and Oncaea perhaps representing the former. Clauso- calanus and Oithona comprised 99 per cent of the first tow, the second tow was evenly divided between Oithona and Cala- nus, and no single species of the third tow stood out with any prominence. Nine of the species (56 per cent) were each con- fined to one of the tows, and only a single species was present in all three tows. These three tows thus present considerable diversity in the surface distribution of the copepods, appar- ently due to the time of day at which the hauls were made. 74 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 61 December 28, 1928; 38° 29’ S, 94° 14’ W; bottom depth, 3299 m; 26 species Depth of tow, m 0 50 100 Temperature, °C 16.9 14.0 10.7 Salinity, 0/oo 34.0 33.9 34.0 Volume of tow, cm® 320 36 36 Galocalanusipavyonmay-riein lace a plumulosuSes cytes tts <-ee = a f 4 StylinemiSmas sae eran 2 Clausocalanus arcuicornis........ f f Eucalanus mucronatus........... - 1 Euchinellay brevis. cert -ra ae 4 c PANE CWR ET 5 oo oeeneo se oooT 1 filo Eine Aemewaaeted cane oor 1 NOSbLAtae eee cist vrente iekenetane ae 2 ce Heterorhabdus papilliger......... a5 ec 2 Heterostylites longicornis........ Mecynocera clausi.............- ass a c Microcalanus pygmaeus.......... a 1 Depth of tow, m 0 50 100 Density (op) Hydrogen-ion conc. (pH) Length of tow, miles 15 ite ih ier Neocalanus gracilis............. 1 LEMMICOLUIST steve eis eee @ithona breviconnis. | «ose. .os: SLMS erase ister ae ee e SPINIGOSEGIS thee ys sie ersesr ese ws c Onthonmammanaseeeee eee eras wt eg Pp mes Scolecithnixedanades. seen eee oe oe Undinulatdarwintts ems. ce: Vettoria granulosa. >... -5---.-- Ree PO! The temperature was still low at the surface and dropped 6° in 100 meters; the salinity and hydrogen-ion concentration were moderate and constant. Four species were found at the surface, 13 in the 50-meter tow, and 19 in the 100-meter tow. Seventeen species (65 per cent) were each confined to a single tow and only 1 was present in all three tows. The length of the surface tow was four-tenths greater than that of the other two tows, but its volume was nine times as large. Since it contained but 4 copepod species, 1 of which was represented by a single specimen, its bulk was manifestly due to plankton other than the copepods. The 50-meter tow contained 13 species, but more than 90 per cent of its copepods were Mecynocera clausi. Similarly, development stages of the 3 species of Oithona made up a large part of the 100-meter tow. A. December . B. December BETWEEN STATIONS 61 AND 62 28, 1928, 115 50™ p.m. to 2" a.m.; 37° 35’ S, 93° 35’ W 29, 1928, 25 to 28 45™ a.m.; 37° 34’ S, 93° 35’ W 36 species Location of tow A B Location of tow A B Volume of tow, cm® 36 32 Length of tow, miles 0.4 Oh) Acantial dana es i fests ctin ase scission 1 Oncaeammediterraneasy aceite) toni eee f f Acrocalanlis eracwisieeie rere imac oie oe 1 a Seth aleces heen aC MOOR o Wao For c f Galocalanusiplumulosisasa eae ee f FIROLWO) OF aero geod Mn Amare dare o ond r < Gandaciarsimaplexnr mew pele siareyn sieerice os en tee a if SUMING. citicsescvs.a Goce ais ens artis eee eee c f Glaisocalanustarcuicoris.).. oc 1-46. =s- === c a VEMUStALS Ac vse ieee vcs aocite = Shere RetOR a c ALI RGAE Siesppens ravens cscanya a tastelesscsvslecss Suniel savers c a Paracalanusiparvus;. cenit f a Gonycaeus:agiliss.--rgs 1 Sapphirina angusta....--....-. 1 rc Harran lal cariiatayey. ice ei ee f f auronitens=cer oc seri saree oe Z (HONG dow cgho ae aoe ome r 52 Scolecithricella bradyi.......... f r if CU is ew aaa te none Bcb OS OE a a c Scolecithrixidanaeses.. 5) eee f f Gila wlay rye eatohesse arcyote de sacre r r Undeuchaeta plumosa.......... 3 PLAGHIS Hearted ata eros r et Wndinulaycarolines jie eee c GOSERAL ANE crap etteycusbetoa ps ntennisre a c c darwintls. aces. see eeee eee a a a These are the first three of a series of nine surface tows taken between stations 63 and 64 on three successive nights. Two of the three here recorded were taken before midnight and one just after midnight of the same night. These three tows totaled 50 species, 39 in the first, 35 in the second, and 33 in the third tow. Sixteen species (32 per cent) were each con- fined to one of the tows, and 23 species, or almost half, were present in all three tows. Corycaeus, Farranula, and Oncaea were again abundant at the surface in all three tows, and Megacalanus and Undeuchaeta reappeared from below. But not a solitary specimen of any species of Oithona appeared. In the tropics Candacia aethiopica is more often found in the deeper tows than at the surface. Megacalanus and Undeu- chaeta appeared here at the surface earlier in the night, the first tow closing at 9 p.M., and Candacia aethiopica appeared later, the second tow running to midnight. Evidently a definite time cannot be fixed for the appearance of any species at the surface, since that time may vary by at least 3 hours. LISTS OF SPECIES BY STATIONS 79 BETWEEN STATIONS 63 AND 64 (0b) A. January 2, 1929, 25 to 4" a.m.; 32° 00’ S, 88° 52’ W B. January 2, 1929, 45 to 8b a.m.; 31° 58’ S, 88° 50’ W C. January 2, 1929, 10> to 12" p.m.; 31° 50’ S, 88° 22’ W 44 species Location of tow A B Cc Location of tow A B Cc Volume of tow, cm’ 32 36 36 Length of tow, miles 0.1 0.1 0.2 PANGAN CARG anaes emncir. aeieciiocc kia c rc Neocalanus gracilis............-. Be r : MERI SENS sepa ve tava syaril oases as f c c LODUSH Ose as seicieiercve cue oe a of 2 Werocalanus sibbenas.. sees os oc f Oithona brevicornis............ 1 PACTS rey cyte ove isiers ya ccc otetene a r r Oncaealcurtaby eran cbie sees vo: Candaciaibispinosaj.4.s)e sls eee 2 NILE Chita epetceeer tect cop slevsa statues sere c 1 lone pou doaDmbadoedses 2 mediterraneay oe sa. aie sos f f MOIniGteths o gui ane Seo CSO 2 MUMUt Ae es eyeesies «2 San a r a Sinjold:. se yomoaseodeolae aoe 1 MOLOPAom eee se crsshevs visbsceiebers a Clausocalanus arcuicornis........ a c c SUMS ence e cece aah eaets r ARCANE. sac HEISE Se CI ae Be f SUD Gil istrserpets ate cee ects. 3,0 teste tee r ee Gonycaeusacilists sac cm se «65ers f Genellaeer ey. Mteracrncrs. ceacans ae c 2 CATS Meer sterayene eres Aces cl onset ai «tes f MEMUUSLamey paerran corse eisectse sis c aA f GUASSISCULUS Meterayheeieiererael cae r be Paracalanus parvus............. f a c Urals rreree eee. fav k tenets eas fi 1 PY SMACUS Ae < oie ac ures sce ee oe a f r EVDIGUS RAIEy a fatein, osc eraves Ba srageis 2 Be Phaennaspiniferaia.:.-.--% 1-4 5. 2 ‘ Bchaetakspinosaly a2 e 4 -)ssre-e <2 sie oe 1 Pleuromamma gracilis.......... oe Ms f emanrih, CliiniHias codes coueobonOE c f Pseudocalanus minutus......... a a c pub DU latent cris ciesorriee Grete 1 Sapphirina auronitens........... a Be il MOSULAUAK erarse arse Se iste o sys ees c 1 c Scolecithricella bradyi. ......... f Megacalanus longicornis......... 4 Undeuchaeta major............. 5 , Microcalanus pusillus............ a Windinwlavcarolige sae cee: ee r r PY PIMACUS te ryetcie caer levees. « a f Ganwinlienvp seen r-cs catia oles a a a This is the second group of three nocturnal tows all taken on the same day, two in the early morning, and one in the late evening. The three yielded 44 species, 32 in A, 17 in B, and 22 in C. Twenty-six species (60 per cent) were each confined to a single tow and 9 were present in all three tows. Here also we find Megacalanus and Undeuchaeta coming up from below, and Corycaeus and Oncaea present in tows A and C, but almost lacking in B. One specimen of Ozthona was found in B, but none in A or C. Except for the 1000-meter tow at station 64, tow C contained the only record for Euchaeta spinosa. 80 COPEPODS OF LAST CRUISE OF CARNEGIE BETWEEN STATIONS 63 AND 64 (c) A. January 3, 1929, 125 to 2 a.m.; 31° 51’ S, 88° 21’ W B. January 3, 1929, 25 to 44 a.m.; 31° 52’ S, 88° 20’ W C. January 3, 1929, 45 to 75 30™ a.m.; 31° 54’ S, 88° 18’ W 37 species Location of tow A B C Location of tow A B ( Volume of tow, cm? 36 36 36 Length of tow, miles Opt 0.1 0.1 iAcartiaidanaeaerencier ery re tesreree c Microcalanus pusillus........... se site 1 MePliPeNnS weiss hed yes tonic r c PMBUCIANS: oo socndadee iicasbar 3) Acrocalantis gibbers. ...9...0-..4- r < c QRAGIsheety. mteremerscis iis ctetsseis a r c similis haem byes ies oes ns c a Candacia bispinosa.............. 1 Oncaeaycurtatin eee ee cst = 2 ee. Clausocalanus arcuicornis........ a r c PEGI EN, dcetan SEO E cen SORE RE r c RULCAEUS asses Pe sselerac lola s ccs f 3 mediterraneaneemmrsiie. = nei: 3 Clytemnestra rostrata........... 2 Minuitae creates. css r c c Cony cacuspautusica.. cade one 1 MOLOPAl es Acta sats eas aiegakes 6 hes at 1 f Maran lancUntarn 1 ace serene a 1 a Venustarst. sacwostree see ms r TOSGLAt AMC tucues. moa cues eres Pe a r Paracalanus panvuseereeiee eee: c c c Mecynocera clausi®. .. oo-5..6=- + 85 a a PYZIMACUS. eae eee et a: f r Megacalanus longicornis......... as oe 2 Pseudocalanus minutus......... iF r f Microcalanus pusillus............ Ae 1 Undinula darwinii.............. c PY SIMAGUS ce cies ctes eye 6 sieves : A Vettoria granulosa....... 1 INeocalanus eracilisea4. 6 sae cor we ee f These tows were made at the regular station depths. The temperature was moderate at the surface and dropped 5° in the 100 meters, but the salinity and hydrogen-ion concen- tration remained practically constant. Eleven species were found at the surface, 13 in the 50-meter tow, and 29 in the 100-meter tow. Sixteen species (51 per cent) were each con- fined to a single depth and 7 were present at all three depths. Corycaeus was reduced to a single specimen in the 100-meter tow; Farranula and Oithona were confined to the two deeper tows and did not appear at the surface; Oncaea was dis- tributed at all three depths. Candacia, Megacalanus, and Neocalanus were found only in the 100-meter tow, and hence had descended from the surface, where they had been found earlier in the morning, but had not gone below 100 meters. R> COPEPODS OF LAST CRUISE OF CARNEGIE STATION 64 (5) January 3, 1929; 31° 54’ S, 88° 17’ W; bottom depth, 3879 m; 74 species Acartiandamaese es. occ cca ti neaseren f Gaidius tenuispinus.............. 3 Qneaea-mediaieaa: ose] eee 1 MES SENS se /ehs arevererssw ave rare r Haloptilus acutifrons............. 1 mediterranea’ => ae) ee eee r Werocalanus\graciiS-)- eee eee c longicomnise ane eres 1 NOCOPA. ete sie SE ee r Amallophoraitypica-).-1)- seer 29 pliumosuszhicae ee Ee ae 1 Similisis)) cs, 4... 6s eee f Amallothrixvalidaley tee sists 2 Heterorhabdus abyssalis.......... 3 tenéllani.ncunnuieosmoe eee 3 Centropages calaninus............ 1 GOMPAaCtusme se eres: eee ee 19 VOMUStal 2.3.4 cosas eee ee c Chiridiella sp., immature.......... 3 Papillig ene. ser ietactescierasr eee 1 Onchocalanus cristatus............ 19 (Ghiridws poppeinne seer eee eee. 19 | Heterostylites longicornis......... ig trigOniceDpS., ...-\4-+. ee eee 1° Clausocalanus arcuicornis......... c ophothrixfrontalis,...s..+ sss ser 1 Rareuchaeta incisal ae eee 49 Gonycaeuswaccusyescmeeeeaeeeees 2 Nine IROE -ooccoomonsacooas 1 Phaenna) spinilerass see 1 Pegs Bese tontedsieneyaysyercteosde Stez= vers 1 Wuciertiarclalsiiegereeyseee retainer: 3 Phyllopus helgaey- ==: 5--eeeeee 39 JONGISEW LIS). eele ce s.e checkcele Merete 3 flaviconniSAsen sake «cid actise eee 1 Pleuromamma abdominalis........ 2 Bucalanusterassusas sa2 .2022 420 1 longicornishe ty. oe ei 4 gracilis... ...:)....:10..e eee a elongatusess)s25e6 226d ts,ccnl ene 3 Mecynoceraiclausin.ly.ee eee eae c Tobusta).... 00.00 eee eee 3 MUUGKOnatuS «22.526 < cies os 2 Megacalanus longicornis.......... 1 xiphias®).,...°2 42) 5 Buchaeta acutas: = 22:5 e0 06 a6 oe 2 PULNICE DS aye aes aoe see hae 2 Pseudochirella divaricata.......... 19 SPinOsa (ose ess Se aactaa din dnems f Metridiatlongaten. asc ace or 4 Scaphocalanus magnus............ 1° Euchirella intermedia............. 3 hIiCenst ey oh. Sel. ere 2 Scolecithricella auropecten........ 5 IIESSIMENSISE Meee celine 1 PRIMCEPS ee che ch ore cee hears 39 bradyik ..: .. <2. ata oH GOStAtAl ase ceinmisiets cerseie sitnas tio) Neccalanusteracilisn.....e een eee: 2 Scolecithnrixidanae:..- eee eras 2 Gaetanusiarmigems. yoeceh once eee 4 LODUSHOGE. wk. so Slut pee ere es 1 Undeuchaeta major.............. 3 kruppii, immature........... yey! || (Oldetere Storie. oe een op ocasranoac r PlWUMOSA 0.6. nce sae 3 101) (Sieh oes enact eee) separ ee ore 1 SPINIZOStHIS =... Ae. eee eee 2 Wndmulaydarwintis. eee f MUMOGS teeter eves ee sec ewtes 3 @ncaeakconiferawes. anette ct c WValdiviella minor:.. 2.5 4eeeeeeeeee 1 (Gaidiisatinism- er oem sie ere 1 Curiae eek tet ace eee f This is the only instance during the entire cruise when a towing was made below 100 meters. Here the net was lowered to 1000 meters, drawn horizontally for 160 meters, and then raised to the surface. The temperature was 3°8 C; the salinity, 34.3 0/00; the density, 32.0; the hydrogen-ion concentration, 7.76; volume of tow, 64 cm’; length of tow, 0.1 mile. Since the net employed could not be closed, we have a combination of a horizontal tow at a depth of 1000 meters and a vertical tow from 1000 meters to the surface. As would be expected, we find here many species (16) which were not obtained in any other tow, and 4 others 1 of which was found elsewhere in a 100-meter tow and 3 ina surface tow. Another noteworthy fact is that 59 of the 74 species (80 per cent) were represented by 5 individuals or less, 27 of them by solitary specimens. Hence, although this deep tow added materially to the num- ber of species obtained, it was very meager in individual specimens. Pleuromamma gracilis is recorded as abundant and 5 species are recorded as common; these are all, except Oncaea contfera, abundant in the upper 100 meters, and of course may have been obtained there as the net was drawn to the surface. Since the net was drawn horizontally at a depth of 1000 meters for a reasonable distance, the paucity of speci- mens in the case of the 9 species mentioned above would seem to suggest that none of them congregates at a depth of 1000 meters. On the contrary, their downward migration during the daytime probably stops at a level between 100 and 1000 meters. That would explain why they were not taken in the regular 100-meter tow, and why so few of them were captured as the net passed vertically upward through the level where they had stopped. LISTS OF SPECIES BY STATIONS 83 BETWEEN STATIONS 64 AND 65 (a) A. January 3, 1929, 10° to 125 p.m.; 31° 52’ S, 87° 51’ W B. January 4, 1929, 0% to 25 a.m.; 31° 52’ S, 87° 46’ W 40 species Location of tow A B Location of tow A B Volume of tow, cm* 32 32 Length of tow, miles 0.6 2.4 INGArTEy GENEISs .coaeeneks Gan orone Somme cron c r Neocalanustrobustions ieee ieee ?) REA TEENS. 5 feted bc amas Cee hater c c CEMULCORNISS sepa scissors te eee a6 r NGEOGAANUS PID Dela sc) ire cts rs rod es dre va Oithonaysimilisp epee ere eee eee r SRAGIIS = wmetey shay Rafe sear seers nest Covaucis, Asante cits c r Oncaeaicurta, 005 see cu. s oe cseusiapo ance ett f r Ganda ciamionveriGain cancers acu es 2 MEGA payne ciel snrs etetne cases leone EP r Siivaia) recat, Ses eae aoe Eee OE eon 3 Mediterranea: 2).6:4 vane ieee r r Glansocalants/arcuiconniS.- e iciys- le - f MENU EA isonsyo ss as s2) hove ORO Eee a c HIT CALUS aay yrs es cycrspetepcen ewer fcvytare f + MOULOPAlyaracrerctevciss cy ose Aah renee f c Gly temmnestrasnostrataley-i te se eecictere cleaners © we SUMMITS aes cy, otehacesesace cuaeckevataiaetnvekeerst ae r Ey (GWOnyCACUSAGIIS pasar naereretere ee ates ae arava 5) oes 1 temellare vans cet ovaiivens tenor-us si ehs oy sukone eae f c GLASSLUSCULUS ey ere sctay sta eycke ons: csaearos evap onsroneys Re 5 WeMUSlaie raat, srs ecsesieysei ec saets, avavshar sues aera r f SDECIOSU Sere beN reer ie Ton atiekeer 3 haracalanusipalvillS aarti iota a a amram lanGa nina tase soy x Aesreteeyeie ay eeuers ofeve r PYM CUSH eivec acs etiers Obed terete aver peey f f GUT pee Nn Or eo Or eee Biotin: c c Pleuromammarygracilistas ance ceee see f 3 (GAG Gy tec Sao ee oO Ore aera nc a 3 Pseud ocalantisnninutusperrerteeie eitrt set f f MOSEL Aer pe yess fee elcr anch-y op fei etien sralidie at eretehe c c Sapphinuiavopalinarpeayeeiiese sire a eietervter 1 Macrosetella gracilis. 0.02.0. 0c- snes s sue 2 Scolecithrixidanaey.n4+- .-----.-+5-6 2 3 Microsetella norvegica.......... ie 2 oe Calanus propinquus............. a a a LOSCA As iste secs d Sa vie deniajens f f Calocalanus plumulosus.......... 1 Neocalanus gracilis............. 2 (Gandaciamonvericas se eee 1 Oithonavattenuatas- ss. ace - 2 pachydactyla =. - mere secee 1 plumitteral mere cere e erele cise ee 2 5 Canthocalanus pauper........... te 1 Simiilisseegteyere Chait ie ciate. ees 2 Clytemnestra rostrata. .......... a ie 3 Oithoninaynanae eee oe eee oe 1 scutellatary: amr cyyere seine sine Oncaea cuntatyesrierico sce a> es cs an ae Ti Corycaeus crassiusculus.......... a c c 1X FE cor into o cot Oca Re NOTE f ce Pe fa\ohoeh USS oo aolpigg aotearoa too r TTLIMUUCalsystey. etegee revere es Grass ois f f KODUSBUSE. ieee eli fe f Calantissminolere.- eee eerie ea f f PROPING WMS) eyes tereiei-eepreneer es 6h 3 c (GalocalanusipavGnen eerie ae 1 plumnulosusmery terete tak ee ai r Sine oomastecooroeceds se 5 f Gandaciaveinplexcs eerie 1 Centropages calaninus........... By Clytemnestra rostrata........... 1 Scutellatars- te acre ceeeritne 2 Gopiliayquadratae=. sarecsteaer rt: 1 VALE OA seays, tegtiecene totes eietauses sitions She 1 Corycaeus crassiusculus.......... a 2 f giesbrechititwmeseyerieieccct tar if ne longisty listen scirit eis tie ot f OVALISNs or nee stee nea sete cs 2) JDL OOO NDE SS Grcnckncags GCL OECRORO ICO. rat r SPCGLOSUS' Ae) toms iiays tezas wisn 1 me § Danodes plumata, n. gen. and n. sp. 52) Eucalanus attenuatus............ Se a a GEASSUSs ssi eicenocetone aneieh oheraxcke ais fo a f elompatust pyc ocrsivsierenstsei-toke a a f MONACKUS mre eerie tetas 1 Buchaetasmaninae seman reine r f f Huchirellalbreviseee rere ase 3 Haloptilus longicornis............ f The temperature, salinity, and hydrogen-ion concentration were all high at the surface; the first fell 9° in the 100 meters and the other two diminished a little. Twenty-two species were taken at the surface, 25 in the 50-meter tow, and 33 in the 100-meter tow. Thirty-two species (61 per cent) were restricted to a single tow and 8 were found in all three tows. The Eucalanus species were again conspicuous in the two Depth of tow, m 0 50 100 Density (ctp) 24.0 D0) 26.4 Hydrogen-ion conc. (pH) 8.17 8.06 7.88 Length of tow, miles iY 1.4 1.4 Haloptilus oxycephalus......... Se Aa 1 Heterorhabdus papilliger........ 2 Labidocera detruncata.......... f Lubbockia squillimana.......... ae 3 4 LMC CNE COWS: .ocusonoconeave oo f ae GUinitare aus sees enuede re erste acs 2 anc OLS aerate 2 Mecynocera clausi............. See f f Microsetellayrosea= = ase em ee f @ithonarattentiatass ere rieer rin 5A f f plumiferas: seen cee Ss 5 én Simulis:(. sywcoe cre ener eke f f a SPIMILOSthis) er eels 2 ae Oncaeaiminitasen cee eee c f a VENUS EA. 250 cts, css; -he nieaeo es c f a Onchocalanus nudipes, n. sp... .. He 5 eis Paracalanus parvus............. c f f Phaenna spinifera.............. 3 Pleuromamma gracilis.......... c Pseudocalanus minutus......... a ro c Rhincalanus cornutus........... 2 1 3 Sapphirina angusta............. 1 5 AULONILEMSe ese ee aces 1 nigromaculata............. a si 3 Memorardiscandata sss 2 ees 2 Windinuwlatvulcanismeettetten eis: 1 2 5 deeper tows, but only a single specimen was found at the surface. Five specimens of the new Onchocalanus species were taken in the 50-meter tow, and 5 of the new genus Danodes at the surface. The Corycaeus and Oncaea species were well distributed in all three tows. Haloptilus, Lubbockia, and Lucicutia were all restricted to the 100-meter tow, which contains one of two records of Lucicutia curta for the cruise. LISTS OF SPECIES BY STATIONS 95 STATION 75 February 14, 1929; 14° 15’ S, 92° 05’ W; bottom depth, 3480 m; 56 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 22.7 20.0 17.8 Density (otp) 24.6 25.4 26.1 Salinity, 0/oo 35.8 S55) 35.4 Hydrogen-ion conc. (pH) 8.18 8.14 8.06 Volume of tow, cm? 48 32 48 Length of tow, miles 0.4 17, 17 NeartiatGanaes stysnr.c icicles cence se 2 f f Lucicutia flavicornis............ f (Chilis hire soos suosecaseduds Be f Ae Mecynocerarclausine eee eet £4 c c PLOPULG MUSE eye ceie ser teret f f Microsetella norvegica.......... a rhe 2 alocalanus/|paviow.-tler errr eee 2 3 TOSG@AN jcnshaces cuansgane ORRIN f f PLUMAULOS USP ays eyes aictere ese) to c Neocalanus gracilis............. ShY]INEMMS ies 5c cfow stereterninias eee ays f hes CENULCOLNIS Seer einer Pa a 3 Candacia bipinnatas=4-19-- ieee eo 2 Oithonavattenuataseeee eer eres f SIM Plextor codecs eocteeis eer ctats 2 4 plumiferays - sciences Re 5 f Clytemnestra rostrata............ ae 1 trot een eon Goto decoded fe c c SOUCEM ata seresctebeisratescraveversveys.s¥eus 1 FOVMKORITES socccdooosceoac : 2 Corycaeus crassiusculus.......... f f Be @ncaeagmedia mere eerie f longastylisiycrscpesaleg- versace erect 1 1 TTI Tamera tie toate men cee ae f c MACKHGUS Hater Ces © f 2 Gandaciassimplexerreere eee f ae Neocalanus gracilis............. f Corycaeus crassiusculus.......... f f 1 robustione.. cn seececsos «ee f GltiDlisen ¢oaspoe ode se dao coe r Oithonasplumiferaseeee ere f Bc lonmeistyliSmeie eer try. 2 Oncaeaminutaseee eee ae eee eee f f SPECLOSUS Here nce erates sapere a: ee 2 VENUSUA's. sic, accuse here ae r hc f Eucalanus elongatus............. 2 Paracalanus' parvus.........---- r f f Puchirellaypulchracee cree lett 1 Pontellina plumatay-. --- eee 2 Rarranitlarcanitna tas sree iscisiereie f Pseudocalanus minutus......... r f MOSCKALA er taste reucyers arta rsre te r f Rhincalanus comutus.-— a Haloptilus longicornis............ “A 1 Scolecithricella bradyi. ......... ee ne 1 Heterorhabdus papilliger......... 1 1 Scolecithrix danae....)-.-11a sce 1 Labidocera detruncata........... r 1 e Wndinulaicaroliz ee eeepeeeeee Cc 1 Lubbockia squillimana........... 2 1 darwintls..20/ snore Hee r Mucicutiavelausitermiemiceeieeie a 3 1 VullpaniS'-j. ct. ssceeeene mice ness r HavicOrniseneee tai a0 as 2 The temperature, salinity, and hydrogen-ion concentration were all high and showed comparatively little variation. Eight species appeared at the surface, 31 in the 50-meter tow, and 13 in the 100-meter tow. Twenty-one species (60 per cent) were each confined to a single tow and only 3 were present in all three tows. The 50-meter tow was twice the volume of the 100-meter tow and very little less than twice the volume of the surface tow, and contained four times as many species as the surface tow and more than twice as many as the 100-meter tow. Only 1 of its species, however, is recorded as abundant, and 3 as common; each of the others was limited to a few individuals. In addition to being limited to 8 species, the surface tow contained very few individuals. Similarly, 5 species in the deepest tow were represented by single specimens and 5 others by 2 specimens apiece, and the remaining 3 species were recorded as “‘few.”’ LISTS OF SPECIES BY STATIONS 99 STATION 80 February 24, 1929; 12° 39’ S, 117° 22’ W; bottom depth, 3515 m; 54 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 26.0 25.9 Density (otp) WET 24.0 Salinity, o/oo 35.9 35.9 Hydrogen-ion concentration (pH) 8.20 8.19 Volume of tow, cm’ 64 96 Length of tow, miles 0.4 1.0 [NGERAHE GENE thers orca o cioeacnoiake eae aint f f Rarranulascarinatal..)2 2a c c ACCA US eA GONIS, oaunagoeoseenen senor c ae ROSCLALANS tee sycacrs ciel 55 coon avacccvesacons fi Galocalanus)pawor aac. eres aie creel 2 cs Megacalanus longicornis®)) 22-46-1145 er a Gandaciatsimplextyase lee eee c Microcalanus pygmaeus.................. 2 Gentropages Galaninmiseye i. reeesine ita 2 Microsetellasnosea. a)... recline 1 r (Copiliaquadtratamanee eee errr ets 3 INeocalanusypracilisy 42.2.2. saci iets 2 Corycaeus crassiusculus............. Bega os f © RODUSEIOIy aist= sist 4)< =< 7 ctisciene eee f Chins UGe ome ooone goeoe eunooCHonEDeOEe f @ithonajattenuata..12:5-..-- sees sete c PRIS. c ocoocnoadeborsobcoudeeuoet - f Simillise a. oasaeommmagerecsagaecooscc 2 a HaIKSCE Sac onecobagdon eo dbodesa mo meee f 2 SPANILOS WHS ewe cons aye coy anccs eras store Onn a PichactasaGutase nent here aertcre ccc ahs r Onceaeakvenustareerieriy ite ceili titers Ic MDVATAA TA eee gays cucyend sees ecoueyans apeee eusysveusceteeyre 1 c Paracalanusipamvtlseeer ill -)-tititeet c Buchirellavcunticaudamsay eerie sei he 2 Bontellimatpl unaertalerereie -iel-incent- herein eatete 1 annanulascaninatamereiertystiietiieierrarirrar a a Pseudocalantus mimUtus\ae <1. +i tierra 4 f TOS tried Cable payee ey Vavelavess. sieve wleveucusrsceiSues0y arerets a Scolecithnixadanadeseerty ic ail eitierneels f WabidoceratdetuumGatals isi sii) 2 er-teretie toe c The temperature, salinity, and hydrogen-ion concentration were all high and practically unchanged at the two depths. Eleven species appeared at the surface and 27 species in the 50-meter tow. Twenty-four species (75 per cent) were found in one tow and not in the other, and 7 species were present in both tows. Euchirella and Megacalanus were found only in the deeper tow; the other four deep-water genera did not occur at all in this locality. Corycaeus and Farranula were divided as before between the two tows, and the 2 species of Farranula constituted a large percentage of the surface tow, but Oithona, except for 2 specimens, and Oncaea were not present at the surface. STATION 84 March 4, 1929; 17° 11’ S, 133° 18’ W; bottom depth, 4121 m; 37 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 27.8 Hiss Density (orp) 233 23.8 Salinity, 0/00 SOa2 36.4 Hydrogen-ion concentration (pH) 8.23 8.21 Volume of tow, cm’ 32 64 Length of tow, miles 0.1 0.5 (Acar tian danae ape recieiricleta aie cies) eeratstoreie seeds f c EAE, MORVA. oncogebnousayodwdwAdoo @ zy Acrocalanusionacilisatemi itt etira-iscichels ire: f abidocerardetrumcatarcics. 11 seerieanrerls 1 Galocalanvisipavoneeeerer tr) terete ttc: 2 2 Pubbocktarsauallimayale a. terete reac f SHUN an one acand cone Soo uleDOD UD 1 —- ILPCHOMHE, GERAOMUNG, « oo aonepansoeonecccs 1 Candaciapbispinosay meee nieres site isier ser c MeGymoGeranG ausinet- gedit) ie ya retire f Simplexee,- cle pis sae lene oecne eee se a Megacalanus longicornis..............--. 2 Gentropagesicalaninuseem. sete eee c Microcalanus pygmaeus..........-....-.. f @lausocalanusiarcuicorniSe seen ratte eee f Microsetellamroseatd.<.%.. is2 2 ct errerert es f (Gopiliaywitireaie. prsctecbes ste rcteret Sekt ete eos 2 INeocalanusieracilis, ye eer merier tener: 2 Gony.cacusicrassilisculusmerer rt yaiettene ts a a @ithonasattentiatalson... ose ieeertateetere @ EKKO Rd pranios Otinins Gund GOO o0.0 Do mona r SIMMS erates oF sc2 as2. osteo eee ie eet : a lon pistylisi;...%:5ccte,2 ayeqecess steretssn cus iereretese 4 @ncaeasGULtan ev. tore. ccercstealereten ote eters f ae PUM 35 ood s eevees Sobroeileen ferme scree 3 ATUATLUCAs 3 oro s.:s sveudie caesé, des oes erste eereteore f SPECIOSUS setcysceie ifs ai cide ey seetetere eichevor gent oke f is WOOGIE MAMA oD aco dc acon oo neo gon c Encalanusrattentatus ee cemeteries 1 leioal Chey oyfegeeebSocaocnnanesonondd0e f EuchaetaaGutale ce crs rier er ieeiie aceiere 5 Rontellinay plumatacmeeneee er retterttrerers 1 3 TYVADIM Als aye os syeys 2 fort etha se ene 2 epatere ayisisleye as ots a Pseudocalanus minutus... 92 ee cere 1 Bianranilatca Lt talanreieriiiereiieie eicieioiiere iter a a Scolecithrix damaereseiiseieie ce eisieitetenea te oO a Gib bilayer eseps vere: cues spe ery cians) everctenertsva= f LISTS OF SPECIES BY STATIONS The temperature, salinity, and hydrogen-ion concentration were all high and changed very little. Twelve species were found at the surface and 31 in the 50-meter tow. Thirty-one species (84 per cent) were present in one tow and not in the 103 other, and 6 were found in both tows. Corycaeus, Oithona, and Oncaea were much more abundant in the deeper tow; Far- ranula was divided between the two tows, but more abundant at the surface, where it formed a large percentage of the total. STATION 85 March 6, 1929; 17° 12’ S, 136° 37’ W; bottom depth, 3791 m; 35 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 27.9 27.8 Density (ctr) 23.3 PSS) Salinity, 0/00 SOR, 36.2 Hydrogen-ion concentration (pH) 8.22 8.22 Volume of tow, em? 36 64 Length of tow, miles 0.1 0.4 A\cartlag ama Cay rstsiayaaretessterss cists eve Sev cucleyeienel = re c Microcalanus py maeusn.. serial serieterster ete f PAlcLOGal amish era Cllisemmtrrsrrtsaroicreircastaierereters 1 Microsetella rosea 35..405c sence 1 { MOM NM Bacsoeusoaeancserddoonsocone f INeocalanusreracilisnaeeer seein ieee { (Calanussminorse = cyacis ss eeeicisre cis setsvss se as f FODUSHOG «eerste tele eee teh ee © (Gandaciay bispinoSalys + «sci i= ale ee = a @ithonayattenuatasy-y ieee ee eee c sin Sse cceeaedort Sapo eon mama be a Slat Sa eeRA eee Ais Pn Ate och sox tc c (Copiliaidenticulatane cee ssc rere oe 1 SPINILOSULIS Leyte) Porter rey eked eee c Corycaeus crassiusculus................... r c Onca caarninutarerrmrrterrst serene c GIULOIING2S o oc ciaereleIIa a i ie orate neterainen 2 es Paracalanusspanvylseeeee eee f SPECIOSUS sieges ania et oe Gon sicieisce ate sue dee tina ayer c phaenna¥spiniteraky acct eke cer eee f ucalanusrattentiatuse. ss - t= o-stre f Pleuromammagracilise =. «2s sierra 1 Cloneeitcegaccoser oro cer cae cee onee f Rontellinasplumatalyjas sere een 5 EB nchaetabmaninaee eter tat am ceien verter: a Pseudocalanusimai nuts qr ret tee c BUG hinellalcurticallGan sere errs recantaricen 3 Sapp hiinagen es tale tier 1 dain vale: Galstereiel5 ponaeoasose oe nadadoule a a DMCC. cosas saoaheousuoasnages 1 BID DUA arcs clears users «pels Sq Jos ose esas 2 Scolecithriscrdamae eer y ersten sts ereteisierereeieiers MOSLEAGA? cic vate sicaye svsiche sts owen e acsvensia cists a r Windinulaadarwinticne ees eeer esac a f Megacalanusiongiconnisee ja. += -e ree e: a The temperature, salinity, and hydrogen-ion concentration were all high and unchanged at the two depths. Eight species were present at the surface and 31 in the 50-meter tow. Thirty-one species (90 per cent) were present in but one of the tows and only 4 were present in both tows. Ozthona and Oncaea were confined to the deeper tow, but Corycaeus and Farranula were divided between the two tows. Candaczia, Eucalanus, and Neocalanus, with many others, were found only at 50 meters. The surface tow contained very few spec- imens besides the 2 species of Farranula recorded as abundant. BETWEEN STATIONS 85 AND 86 March 8, 1929; 17° 48’ S, 140° 49’ W; 20 species Acartiagdana Gap pernty yo svsh seit setee cree c Corycaeus longistylis Acrocalantisipraciismey. «clerks = 1 robustus...... Gandacia norvepicalys.. ie. <=) 5 speciosus...... SIM Plexemnee varies crest eee ae f Farranula carinata. . Centropages calaninus............ f gibbitlan acne Cornycaeusagilisse cece cit = + r rostrata....... GrassiusculuSrer ase aie c Microsetella rosea. . SB Sop seca entire tele: 2 Oncaea minutas qe eee eee NEI Oa eereL aire 2 SIMIIS |e. a 5 save ctvateonrs Re ee ee Bin aWayateedersve akon f VENUStA. 5) <«.ce. cite. Ste ELS Hebonbudircc es c Paracalantis/parjvuss.ce eee Saye Cusp Sava SCSI 4 Pseudocalanus minutus........... ¢ OTT tae c Sapphirina auronitens: ----2-----..0 1 By cicremer hereon 1 Volume of tow, 32 cm*; length, 3 miles; surface only. In this nocturnal tow between stations, 20 copepod species were found, including many that were confined to the deeper tow at the regular station on either side. None of the species was at all abundant, but 7 out of the 20 were recorded as common. 104 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 86 March 9, 1929; 17° 36’ S, 141° 55’ W; bottom depth, 2132 m; 35 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 28.2 27.4 Density (orp) D352 23a Salinity, o/oo 36.1 36.2 Hydrogen-ion concentration (pH) 8.29 8.29 Volume of tow, cm’ 32 34 Length of tow, miles 0.1 0.2 WAcartia: dande's:.ajrr srs ais ste share @ cus ee leeks c Bubbockiatsquillimanaeas- eerie 1 Acrocalanus gracilis. a VOMUStar reece ioysreleys (alee eee a NOGVERICA;.. <)<.1a.5 ere oe ASST N f gibbula: acc se memset. <5. f Paracalanus\parviulsieee ase Cc S151) (2 ee eerie tars Same kerantc c IEC Saad c.oaa0 5 68 cic Meena r Pontellaysecuntier. 1 - ms ss cee 1 Canthocalanus pauper............ 2 TOSULAtA ase eer yee cislenen wc c Pontellinayplimataseeee ae eee f Centropages calaninus............ c Labidocera detruncata............ f Sapphirina auronitens............ f Clytemnestra rostrata............ 5 Bucicutial claus teewseyeicie. sve clever 1 Spinocalanus magnus............. 2 Cony.cacusieatuses sere reae ence r Macrosetella gracilis.............. a Uindinulasyuloanistee eis eee f GrasSstnsGi seein erie retane a LISTS OF SPECIES BY STATIONS Volume of tow, 48 cm?; length, 0.1 mile; time, 7" 50™ to 10" p.m.; surface only. This nocturnal tow yielded 46 species, about as many as were obtained in both tows at each of stations 89 and 90. Nineteen species which were confined to the 50-meter tow at stations 89 and 90, one or both, were 107 here found at the surface. In addition, 13 species were here present at the surface at night which did not appear in the daytime tows at stations 89 and 90. Thirty of the species, therefore, give good evidence of nocturnal migration. Cory- caeus, Farranula, and Oncaea were especially abundant. STATION 90 March 25, 1929; 16° 35’ S, 155° 45’ W; bottom depth, 4630 m; 45 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 28.5 28.6 Density (ctp) 22.6 22.9 Salinity, 0/00 35.4 35.6 Hydrogen-ion concentration (pH) 8.27 8.26 Volume of tow, cm? 34 80 Length of tow, miles 0.6 0.9 CAGAITEUTEN FIO Seo COB DOIG Once Bera errr ote c Rarranulasrostratas- ere eerie Pa eee te f c Acrocalanus gracilis...... aaron Morac f c ahbidocera:detruncatas ener eete f MORAG. op poo CeOO COED Goer E Dome a Macrosetellateracilisses.- 2 eerie of 1 Peeilani (ssn Ol eseray- cele cio) rere rou cieiaere ever eG f Mecynocerasclausin weiss so ceioeecm cea 2 Ae PROP MCMI Sons cdnochene naencosodeec 1 Microcalanus pygmaeus.................. a San dactaubispinosa:, =a fec 2. ss cineca 2 Sian f Microsetellaonorvegicals +2. ..-e.eoeseseee 2 SIMA NO xtyy cress ec ichsie sree ches eee Gescumelereres ara f GOSCA aeye stay cystecavehate ovat one gete cer ares f ientropagescalaninus..-5..2c.cceo:semer es f Oithonatattentatatesr eee seer eile erie f Clausocalanus arcuicornis................. 1 f poluimuferahrs asc oe cie cra cies. artetoaiers f opiiiaidenticulatan.....05 s/c. etree ete sc f c SUMMITS ge yansts sve sens ese| apsveies selene: reveten clepets f Cua dratanerry-qa/-yy-ra ciel) s cerasicvels (cise 1 SPINILOSEHIS ee aerate eases eters Bis 2 VAGOES ob. aao b OHO OOO CD GLE iene OES Bee ia 1 Oncaearmeditarecerismteee esr Noreen aS f BOKY GACUSIANGIICUSs .saiscleis cise ciel =)s scl) 1 IMINUt aero tee ee acetate f c CANE 3% cela Bio RO RLOO DE ce OIcad Can Pee 2 Guiles oa ose Mecsas es DOUS Doe ro Or r GLASHIUSCUIUS tee mye cicleeiteiseelen oe c a VEMUSCaa ete iseves shes cveicheh ster hel sietenetsie nics f f lO KANGs Gena ae cosaeoo Ho oeaneemeets f c Paracalanus)palvllsasacec eee ci) tee creer f BPECLOSUS sersiere leechers versie erst rset teeters: elt ake c c Rontellaytenuiremise--- ptr eee eee f EV DICUSE ia Sia Sere a arcesie) severe clsteusics ores eoae 3 Rontellinasplumataleseene ccm reece 1 oe Bmnchaetaraclita’.. 2c «src stysinee ona te ne f Pseudocalanus minutus.................. c MAINE, scabs sacido BUTECe See ie c a Sapphirina mipromaculatay so... scr <1 iL Betimaniiiia’ Garinatal 2 cis oe vateisteiave evs c a Scolecithnixydanade semen erereeeinc eee a CURE. a itao ater sod cu nt Genoese totes r a Spinocalanuspmapniste ieee eee eae 1 lO en, aoe Amn tee coon os Hames r 2 The temperature, salinity, and hydrogen-ion concentration varied extremely little at the two depths. Twenty-five species were present at the surface and 34 in the 50-meter tow. Thirty-one species (70 per cent) were found in one tow but not in the other, and 14 were common to both tows. Cory- caeus, Farranula, and Oncaea were well distributed between the two tows, but Oithona was much more abundant in the deeper tow. The 50-meter tow was two and a half times as large as the surface tow although its length was only one- half greater. Paracalanus appeared in both tows, but Pseudo- calanus was confined to the deeper tow, along with Calanus and Candacia. 108 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 91 March 27, 1929; 15° 44’ S, 160° 25’ W; bottom depth, 4937 m; 50 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 28.7 28.5 Density (cp) 22.2 22.6 Salinity, 0/oo Som 35.2 Hydrogen-ion concentration (pH) 8.30 8.30 Volume of tow, cm# : 32 32 Length of tow, miles 0.6 0.8 INGERHEVCEMED, oc uosdnoondadudboncnuoneae f f Buchaetalmarinaie eters ore «cleie ole /rtersissieeriete c a [NGOS EMIE ACIS. 5 ooconcasneonsecwbont c c Euchirellaicugticauda,.\.. 0.2. == bc 4 SMCS o sonenenseoosouesEuooueer 2 PUN GLa wernt rts oarior.sevtcfeyee teases tetele MOMIGNIG so ocacdoooe on coecotsen ete a f Rarranulascanitatasy eric. 212 -'oeieneine c a Galamisiminoias «tet eae dan tacpoesiene uses f gb ullaleratereyeseteget oucteye oie. shales Se ysiebotanetete f Galocalanntsipayomnmener tetas tlre orien 1 RCN Bsc cée0 onncnodogD ManSeerRoEod oc ua r GandaeiaibispinOsamer tren eter reer cr 1 TOStrata mer reer ac Ath es ccs em ere f f @lausocalanusarcuicornisy yj.) keer e 2 Wabidoceraldetruncatan-:-e-2-) -e o f Copiliavdenticulata emir tieitel< ele ee 1 4 Microcalantsipusilusseeery eel 1 GURGENA 5 A oeegn ooo soocceecosdaonoT ae 1 MPAUEKUSs 6 do guncapoaGgooneD esa eoUN oy f (CORTAMIS AMS 555 sooedocoogomeodsducdsO6 f Microsetellasroseascrerieieneisisi rele = rele aE f ANANCUBs 5 wananeicAddasdoeoapoogDEod { INeocalantisirobustioneemn esti itiie-itels 1 GATUISE oe eae os eae cnsleeev ose en ies cubeenetets c @ithonalplomuferasssan eee ees ice f GASH ecerorcteiste < eet tees ie syns bevecenene ie Strihl (caeeereiaen ta aba ce oo eo aOe f GeREsnecilics 9 oto chaste aseensAgoDos 2 c Oncaea .curtalc. 32 jane vedere tae ne: se 2 ste HEC Woe oon ecduntos canes aaa ooncds 1 ME 1a. 3. cxs. ses ale peeane Oh tan sot tere ese inert f fUincilenesanmrns acer reise reeparsterctets a 1 haiti te: Lee ee ATC ae Gcto.cl «ane, omenoc c PKA MAIA wos pp dodooad de aceon edcod< f Similise a aves aon ee ae f NeAUUELIS 3p ear cree heetererar ce eiegeeets she ore) eeteconsie 3 VEMUSCAL sre Sect ie ele oo meee aos, Sos c Irmbatuspsn crac Me srce dente) sire atetcierctereratete ir Patacalantishpany Sassen ire ite c lonpistylisue-aeae ier ee ier f 2 Rontellaglobiancowne eee eee f ONEIe ana dan onmocaad aeeaa hare co toon 4 CENUIEMISH a eee err cite f PRIONIGCHS .¢ coengcendandosg0GcesuboUOS 3 Pseudocalantisimimutuseriyemeoe =i 2 = eral a f FISH rooaraso sop osu soeasseoueoDe Cc f Sapphirina nigromaculata................ 1 (NGDUE o ospaapsosasnonveneDecuouMoT f Scolecithrixidane caer mrt eteeree teri er tial Be a The temperature, salinity, and hydrogen-ion concentration Corycaeus, with 15 species, was especially abundant at the were high and practically the same at both depths. Twenty- surface; Farranula, Otthona, and Oncaea were more abundant seven species were found at the surface and 33 in the 50- in the deeper tow. Although the 50-meter tow was here one- meter tow. Forty species (80 per cent) were present in one third longer than the surface tow, its volume was exactly tow but not in the other, and 10 were found in both tows. — the same. | LISHS OF SPECIES BY STATIONS 109 STATION 92 March 29, 1929; 15° 18’ S, 163° 14’ W; bottom depth, 5530 m; 27 species Depth of tow, m 0 50 Depth of tow, m 0 50 Temperature, °C 28.5 28. Density (ctr) 22.4 22.8 Salinity, 0/oo S558 So Hydrogen-ion concentration (pH) 8.29 8.29 Volume of tow, cm’ 32 32 Length of tow, miles 0.4 0.5 AGATUR GATES 5 oe pang OURO noone aera: c Euchinellaicunticauda™..e vases er 1 PVcroGdlanusegiD beherciaccte ce cricrcaer teers si 2 Barrantlaicaninata snaceere eee c c Grae Ss clos iamendohe poate. cae aeo cia f 2. Slob ulatener.roprteccst neha eunra ect everett: f ais MIONAGHUSH HN eycre ecu hie ie cicieGiawe = evs f ROStEAtAT an at) occ eo ae eee: f c andaciaibispInOsa ec. serene crs ciesveds) se eters sy0 2 Mecynoceraclaustes- cise eee 3 SUMplexoce se tle Sate ots osmOs sa comes 1 Megacalanus longicornis................. 1 lansocalanusjancuiconnis). «2.2... -<:----- f oe Miicrosetellasros@alsy.c.. acca ce Bier eet c opiliaudenticulatacerds-mr-jsetieece ete eee 5 INeocalantustenaciliseee messiness 3 Quadra tarerrcrperica creer ise sienna : 1 @cthonagsinn isaac ce ence eres ie K@Oly. Gaels CrasSimSCUlUSs 4. -iae.se ce eee 4 c SPIMILOSEIIS Hes = se ussecinie ee tarenecetn, sleet 2 PUMIUUS Hs Feiss s ae clo dos ea ee alee acts f Oncacasminutarr rece ne wees eit c f SPECLOSUS ey epeiersials stsbe chstsierdis Si eisteie ais Byaseis a5 f aracalamusspalvyllss asa ncety ee eet f c Ey PIGUS Meteo taxes 1c Sind scien s core Sto we ec 2 Be Pseudocalanus)minutuse © ge cee sss ls f c BGhe ebay Marina enya is eee 2 Centropages calaninus........... as 2 Oithonarattenudtas-eee asec Fe 2 Clausocalanus arcuicornis........ c f pltimiferays ose t-scsrescsoeeesroe f f Clytemnestra scutellata.......... 1 S€tigeDni. seracis seis avers arias ee aig 5 (Copilia denticulata.--..:.---..-- 5 f SUTILISt pede ors sh tenseonicre es seyanete f c Quad ratales ercrayecistcesse-e terete or 2 2 Spinirostrismen ase seme f f AGO CACUSIAGlIShescae ccc cei ne r @Oncdeatmediateer nec ee etnias ore f GrassiusGulussae. sc cictere is sieves 1 a c mediterrameds «ese sees 3 NANVEUS Peer eete eraisccithc suche le sisccccaue : ; IMUM Cale errcreycvete areraare stele ei 5 a c ION PISEY IS eto cccleacieecioterer Tons Se c f VEMUSCA) sey ccjctere vei: steve )clershe a c IMUSIC it ce eres eee Ss r é Paracdlanus panvusss se) seer c c SDECIOSUS a Eel pretse cg de Sees si c c Pontellina plumata............. Sis 3 2 EY DICUS aren reser cteusicesccveyer rere a Ee 4 Pseudocalanus minutus......... f c Danodes plumata, n. gen. and n. sp. 19 ac ae Sapphinmaranpristas eae seers ne 1 Eucalanus attenuatus............ f f ALITOMILENS seers ere: acter tseatel 2 GEASSUS trys) hover toies isi esey spe ee 3 metallina ress ies fecus ¥ or: 1 ClONGALUSH ee setae set cu 5 migromaculatale...).\2)-)..- i 4 Psiichactawimatinal repre ci icrerere ae f f Scolecithrix danae.............. c f ictremMlanCabitataces so eh sis eel 2 a c Windinulatdarwintiee se. aes ee f (CINGIENS 6 aco oon Omer oie f oo Will pariSeetysa sre vicenas fe pees a SD Ua eye ts tarps ates crabcern eresareye f Vettoniavgranulosa.. sense ee Be wt 2 Temperature high, diminishing only about 1° in the 100 meters; salinity moderate, increasing nearly 1 point at the 100-meter depth; hydrogen-ion concentration fairly high, changing scarcely at all. Eight species were found at the surface, 39 in the 50-meter tow, and 46 in the 100-meter tow. Thirty-six species (56 per cent) were confined to a single tow and only 3 were present in all three tows. Corycaeus and Farranula were well distributed in depth and included the 3 species just mentioned, no other genus appearing at all the depths. Candacia and Oncaea were most abundant in the 50- meter tow, and Oizthona in the 100-meter tow. The 100-meter tow was 30 per cent longer than the suface tow and 10 per cent longer than the 50-meter tow, but its proportionate volume was considerably greater. ie COPEPODS OF LAST CRUISE OF CARNEGIE STATION 95 April 24, 1929; 8° 43’ S, 170° 56’ W; bottom depth, 4298 m; 74 species Depth of tow, m 50 100 Depth of tow, m 50 100 Temperature, °C 29.3 28.5 Density (orp) JH ai Dial Salinity, 0/oo 34.9 35.4 Hydrogen-ion concentration (pH) 8.24 8.22 Volume of tow, cm 48 80 Length of tow, miles 1.9 Daw? Acrocalanus pibbetjaertattarteraeiereieerrcet: 2 4 Banranula rostrata. a. aero) -tistieis tree f f MRO Es acu omod a oe cocicin aoOSm oO ROGot c c Haloptilus Jongicornisse. eee eee a lolnfeiteornliss 5 SemAGohace ho7 5 aon nas gor 1 f Wubbockiavaculeatas..n- sii ate 3 IONS oy aoe okan KONO Udon nee a c Scqumllimmanarcns ae pene ucterererseeene rete aes f Amallothnixapropinguak-rrrysrtr arial 3 UCU taNbiCOnnUta sere eer ieee 2 Calanusmminoipsery chee cee acta scree skere f c GLENISTItprecteyepeisitit cas eatenem ee eee ee f Galocalantusipavone reece 1 ds HENMCOl oc eke ome erennmno Ata Oona ae : c Candaciavaethiopicaleer tere eiyeteieteet sie) 4 f Macrosetellateracilis.-. 22. <2 ned. semis cior 2 me ispinOSareer ey aeire tri ee inital cles 4 ae MIBEmNC ee GEIS. com pabeseohoobEeooonc 2 3 OSMMADC . pGn6 cod Gu oo meGoU OOS COOGEE 2 Megacalanus longicornis................. 2 1 Simplexrmcra crete csi ceil neile eheveeleerorees a f Microcalanusjpusillus: 3. : 25.2. ose ets 2 2 CAE on on Concedes Gb obe ane aoapon a c PYPIMACUS ereeys er irete cisayee crs iors eax ooo tetee f Canthocalanus)pallpere meme serie sen oles of 1 Microsetellagnoseamrr rater tetolci-se/ cern tsr ete cree c c (Gentropagesicalanintisiys i nile | donee seo f Neocalanus:pracilisie.g .c.c sc selon eie= -=)pe stone 4 Clausocalanus arcuicornis...............-. f Gc KODUStIONs arene ccm eneherce ces 4 Clytemmestrayrostrata .. oc. ci. eri tec = = 1 Oithonaufall laxeyersset ect tertes cess tezales =) rete 2 2 Coniliandenticulatas merece eee f f plumiferain ctw ceocvere att gero ene ieee f ee Guadratassar perc) ori qavere chose avcretonnie we, Chalets 3 2 SCLIG ER. xtc coscesete yore erent a tedtenetoxelerens ee 2 Witiie odao odo aoooU mone aan area ae 1 : hob) ete ores aoe beac to Soo Oo Ono c c (Cony.caeusfanglicisscers eee ne tyact veer be ie SDIMIFOSETIS meter ae eee erie iehelerare f f GENTE rein Choire ka Orc Att orrctore ono di: 2} Oithoninatnanas-=- see eee eee 2 2 CESUECMWOxccssonwanesocongboaacoo c a OPNCHOA CURE js cones cooocasatacssoapease ie Bi Gis ae nondodebes ganar aaeuddooS 1 TMEIa's fe. aca vad ofa easels epee eerie sat ors f INUTRCHES On teuetenen pee OS EO MeO OOO SO ae r MIMNUta ccs a etors eek eee c a iil och bac. 6a ddan Morceeredat Gucotntd 1 Slur}! oe oiorerometo dala dalce.cat.o Vener c longistylisteee acme acl ck ciciewereere 2 f tenel lays iavcc-chattaueys creistee mares eraser sche 2 OVallis web fetarercteesie tons, cters couse fee gsseve ore, sustshe 3 VEMLUStA Ss tndraneatei oe ee Re oe aacteks a a OLIN saan aes Oo dacdcdols aooma conan. f Raracalanusiparvusaa- ieee eerie eet c Cc SMEGIOSUS yet cheno ts skeredeket s tnicreisiefous stsrelere save 3 Pseudocalanus:minutus,. qeeeree ec. - c c Bucalanusrattenuatusecn meen ene ee eee f f Rhincalanvscomutuseeeeeee reir 1 oe GRASSUSHRC Ptr totter Rene oer f Sapphininalauronitensssnercen itil ar 2 1 Glongatuissnetiercust hemlet ste ewes nit les oes f metallina.... =i-lel f Pseudocalanus minutus........... c Gandaciaysimplexceste cme: tos a This surface tow yielded 16 species, but most of the tow was made up of development stages of Candacia simplex. LISTS OF SPECIES BY STATIONS 113 STATION 96 April 26, 1929; 6° 47’ S, 172° 23’ W; bottom depth, 5269 m; 68 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 29.3 29.2 28.2 Density (orp) 22.1 22.4 232 Salinity, o/oo Son2 85n2 35.6 Hydrogen-ion conc. (pH) 8.23 8.23 8.19 Volume of tow, cm? 48 64 64 Length of tow, miles 0.9 17) 12 INCANCIANG ANAC Mine crscreleley teks exes sus: s Be c Parranulalrostratass ee c f f MEQLIPENS yareyeerac eevee sla = Sete : Haloptilus longicornis.......... a Acrocalanusigracilis:, «cj... sees = a8 ce SPINICEPSee eens aecenew cetera 2 longiCOrniSts)... ese. soos ee os f Le Heterorhabdus papilliger........ 2 MMOMACMUS Hye trcs afeusien ere Maicctsicvsttons 2 Lubbockia squillimana.......... 1 Amallothrix obtusifrons.......... ax 4 WeuGicutiasclausitess see eer @ Galanusiminorene 5 cerr-v-cie oer f a c HaviCOEMis.. cas --teee ieee : : a Galocalanus/pavo.....:-.-:...0: 2 2 Macrosetella gracilis............ 2 2 1 Gandacialbispinosal q.r eee c c Oculatals secre ac ears tisrersie eas 1 MOLVEPICA yw. ao eeis ee cieieisesieoe f f Microcalanus pusillus........... 2 SUM PlEKereyeeicis tise ote cohs coats c a a PY. PIMACUS Hye. te ns aricrera cyeretors a. f f ErunGatalepercthcrmircisiete ats ‘ c f Microsetella rosea.............. a c f Centropages calaninus........... 2 f f Neocalanus'gracilis...... 5. ..0-.-.6 4 Clausocalanus arcuicornis........ f f GOD USEOM esses ce sts pots ersiceer elas, + S: f Clytemnestra rostrata............ ee 1 Oithonavattenuatas..-.,.--64.-6- 2 2 SCUtC Matern selcreustos eect 2h 2 Se Plumiferaresco acme oc see f 2 Copilia denticulata.............. A f 4 SUID epee fee cst tee einer seee f f WILLeA tans REN theca Snares es 2 SPIMIGOSENIS ae sieeve ses eos 4 1 (GonyGaelsiGALusenssc shee oscars if Oncaeatmediamemrerrrccestsrrie fe r GrASSIMSCUIUSe 42 Jen crete es eieteiets t c c AUTRE oppo tetey corn coy in telines /svee.te f c c CUP IUSt ee teyetalatvisraele nie ete alee + e. SiS. osduareecdserssune 3 Piesbrech tien. dates. atin sists be Af 2 VENUS aie crc cen srrseetePecet f a a Iimbatusenrecncie icine: Tr oe i Paracalanus parvus............. f c c longisty listers iicieeiacierenta 20 f f Phaennayspiniferae <2)... = 0s. «= 2 PAURTLL LOS tee yersy epa%ers/eustoleters 2 an ae Pontella tenuiremis............. 1 SPECIOSUS mien erie t ier f f Pontellina plumata............. 1 GY BIGUIS|-tavistesatsierererctavstecctacs x sree f Pseudocalanus minutus......... = c c Eucalanus attenuatus............ f Sapphirina auronitens........... c f CLASSUSEpriye ie Porshe oreo f MIZEOMACU aval. ein ctalstel eke Pa a 2 elongatusterr chick nee e. celenls Scolecithricella minor........... Far 3 Fa Eichaetamarinacnn «ics -< lr. Scolecithnixidanaes... 2 ee c c Harcantlavcarinatalnya. cle ser: c a Undinilavcaroligs asses era 2 CUGC AI fae eietarsievete aicleemeah oust 3 GER RIG eoern Gro arco O00 On f oa ba Ulalewn screeners (iors eaves eres f c Vettoria granulosa.............. 3 The temperature was high and dropped 1° at a depth of 100 meters; the salinity rose and the hydrogen-ion concentra- tion fell, both very slightly. Seventeen species were found at the surface, 41 in the 50-meter tow, and 50 in the 100-meter tow. Thirty-nine species (56 per cent) were each confined to a single tow and 10 were found in all three tows. Corycaeus, Farranula, and Oncaea were well divided among the three tows, but Oithona did not appear at all at the surface. Three of the Candacia species, Eucalanus, Euchaeta, and Undinula were present only in the two deeper tows; Haloptilus, Hetero- rhabdus, Lubbockia, and Lucicutia were confined to the 100- meter tow. The 50-meter and 100-meter tows were each 33 per cent longer than the surface tow and their proportionate volume corresponded exactly. COPEPODS OF LAST CRUISE OF CARNEGIE 114 STATION 97 April 28, 1929; 3° 47’ S, 172° 39’ W; bottom depth, 5253 m; 74 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 28.3 28.0 27.6 Density (ote) 22.4 22-9 23.4 Salinity, 0/oo Sone S9)a33 35.5 Hydrogen-ion conc. (pH) 8.16 8.16 8.15 Volume of tow, cm# 32 36 80 Length of tow, miles (0)5) 0.6 0.6 Acartiardanaews aceite eee c c Haloptilus spiniceps............ ns 2 4 NEcligense tresses ee wees r ae, Heterorhabdus papilliger........ ae ae 1 Werocalanus?gibberasesce see eee a f f Labidocera detruncata.......... 2 RICH NS: 5 ses ee Crao oan ano etc a c c ucicutiawhavicorniss....- > o-ncre ins Sr c LON EICOGNIS Ne Aree sen seme f c ae longiconniSe peas st eec = wrociess Se e 1 MNOS MUS tec GG OOo OD 6.0 f c 2 Macrosetella gracilis............ = 2 Galanustminopeeeseteeae eis c c Mecynocera clausi............- =e 2 HOTUS US eusys stare eres vier eceteasdets aa6 1 Megacalanus longicornis........ ae f 4 Galocalanusspavior naw s.r 2 5 2) Microcalanus pusillus........... a8 or 4 Candacia bispinosa.............. ue 5 f PVP MACUS Heer eeleeee aes chen f f SIM Plex, seen so aie ares Sie Ss 2 “a Sa Microsetella norvegica.......... f 8 truncatas Vis ers woke sescas f f KOSCAR rs See aes erties c c Canthocalanus pauper........... : c ae Miracialefferatas----s-- ae 55: 2 3 Centropages calaninus........... f f 2 Neocalanus gracilis............. i f Clausocalanus arcuicornis........ f f TrObustion-sss.2 wets f c Clytemnestra scutellata.......... 2 1 EOEMULCOLMIS Hea ere sete sete ris eee =r 1 ic Goprlraidenticulatay- 2... «0... f 4 Oithonarattenuataseeeemeeeeiee f Quad rata ver sre ors ete. et- nz tet 2 plumuferameeeeee eee ne 4 f Conycreusiagiliseeesre eer tre 3 Similish fotiac oc ween ere oe f c (ili Goo ican oos Goramec aocoea r Gjoyvinasse Son cocancneanoaae 4 GLASSIMISCHIUS ere erie c @Oncaeakcuntanceas nee 2 IANEUSH Hey oee singleton ce se ies ir at a mediterranea) aeje myers ele longistylicty aioe mercies f f 3 Minutasacencdaeeseo meee c a lubbockiigss seen che ae Similis# mince tenner meee r SPECIOSUS ny opens oh eek ee ar c f VENUSEAY,.. sce e eeu eco c a a EVIPIGUS Weleroks sate eteraue re ee, Pane cre oe f Paracalanus)panvusseeeriaseeece: c a c Eucalanus attenuatus............ f f Pontella tenuiremis............. 3 ChASSUSY Ae aie suc reterasne tenet arrestin 2 1 Pontellina plumata............. ag f 1 elougatustacncc.cscce eee 5 ti Pseudocalanus minutus......... C c c Birchaetaracutae. sameeren f ae Sapphirina angusta............. 3 AMAT UALe ae cis Ses. ohes eerste a = aloes f a c aunonitense eerie 2 = 2 Euchirella brevis: \....5...2.-=- 4 1 mie talllinameerer reer rsrie stele: 2 3 Parranulalcarinatals... ss. =< c c migromaculata erie) lie oe 2 CONGINNAY. Fc. orate ee aeee 50 iD r ovatolanceolata...........: gibbulas be ween see agen ok én bs f Scolecithrixidanaes....5----.---- a c TOStIAtaG Pyeeaee cre arenas ei: a c ‘ Undinnlatcaroligeryte te a -- ae f Haloptilus longicornis............ a GEin iti belo ado nue poecnente a c c The temperature, salinity, and hydrogen-ion concentration were high and changed very little in the 100 meters. Twenty- nine species were found at the surface, 51 in the 50-meter tow, and 45 in the 100-meter tow. Thirty-six species (49 per cent) were each confined to a single tow and 13 were present in all three tows. Corycaeus, Farranula, and Oncaea were divided among the three tows, but Eucalanus, Euchirella, Oithona, and Undinula were found only in the two deeper tows. The surface tow contained one of the two records for Sapphirina ovatolanceolata; the other 4 species of Sapphirina were found, with one exception, in the two higher tows. The two deeper tows were each 20 per cent longer than the sur- face tow; the volume of the 50-meter tow was 10 per cent larger, but that of the 100-meter tow was 150 per cent larger. LISTS OF SPECIES BY STATIONS 115 STATION 98 April 30, 1929; 0° 18’ N, 173° 59’ W; bottom depth, 5599 m; 72 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 27.0 26.9 26.7 Density (ctr) 22.9 23.2 D3e5 Salinity, 0/00 S577 Siac) 35.4 Hydrogen-ion conc. (pH) 8.16 8.16 8.14 Volume of tow, cm? 48 80 96 Length of tow, miles LAS} 123 1s PN GarblaN Gana eric nic chore seus ajo ieceFere eases c De c Harranulayrostratana- ee eeeee c Acrocalanus gibbers..........6-. f a Haloptilus longicornis........... ae se f BLACIIS J. esaels fa,s daisies a c f Labidocera detruncata.......... 2 tes lOnPICOnMIS eyecare terriers f Lucicutia clausue sere eee f Bs HAO MNES ay cat efenae- tetas eienever ore) f ts Macrosetella gracilis............ 1 il 2 (Galamussmin Ore peste cee ois eicisss eve f c oculatals, cs acegasxserteeee 1 MOTSUS erie) yahoo ce oa sires So evey 1 Mecynocera clausi............. 2 Calocalanus plumulosus.......... 1 Microcalanus pusillus........... os ae f Gandaciaybispinosaspee ee cisecnon 2 PYPMACUS. « crie) eenera eee c ie longimanaly a. .c.craeccet el ns sve ab at 4 Microsetella rosea..........-.-. f G c MOGVERACA nis «<< cise .e/e oie ws 2 Neocalanusjeracilis:--o-.-eeeee f f SUMPlEKane oe oe Ses eee ns OR f 5c GODUSUIOG A cin a .ysterste vernon 2 f EMUIMNG AGA wctepsts cloverctecciie sepa. es c c Oithonaattenuatas- se. secre f f 3 Canthocalanus pauper........... 2 if f Heal laine sre ees. crssayacs eee eI 2 re Centropages calaninus........... 2 f f plumiferam cc... <.tsra ee. eee f f Clausocalanus arcuicornis........ a f f Simlish: eevee cs eee ee f f f Clytemnestra rostrata........... D SPINULOSUISeea ye rt ere rte f f SGuitellatalen <..2.a.n--e2te gers s2ies ae Ric 3 Onca@eajconiferae- 42-5. seek 2 Copilia denticulata.............. 1 TMOG Ay. ope rere shore vere aslancietere f Ne Uadratacm terrace erent of 2 TIMILU Came er estate chctorsr gy aoker toe f c a Corycaeus crassiusculus.......... f VENUStAL Mie scars choc vere Stas c a a HULL CLC Ieee ewaper eres ce isteyeratei ede cetera 3 pachos punctatuml4---47 oar Ae ze 2 longistylis: 222 ...c02 estes aes f 1 f WUE ON MNlecoassocouspuboac PUSH 5 ote tase ys, Ses wee 1 Paracalanusipanvus.....5 --- ee a c c BODUSEUS garcsesicscssuens see Sar erasers 1 Fe FPontellinayplumata...«.-.-. 426 c f 3 SBE CLOSUS 5 nxavs ctace cars cect ote re, nesters 5 f c f Rontellopsisiarmata.....-.-.--- 29 S ty ICUS 2a, wyekeur ens « f c c GDN Se cain sec ieee eae 2 ce oy Onchocalanus nudipes, n. sp... .. ise 3 3 ONS eon apes acmcn acta ni Pe 3 Paracalanus aculeatus........:. 2 ACHICUS 2 aay ote stols anyone c ae PAGVUS gaa ce te. sci castes oc f ie f SHEGIOSUSE spetcfe sists fs acre stesso c c Phaennaspiniferaly .1/-sereie) +) feo a Eucalanus attenuatus............ f | Pontella tenuiremis............. i elon patlist amc eaysree telceie o2 f Pontellina plumata............. 4 4 5 Biichaeta acutans. 2 a Gonycaeusiagilisnece ceierreierere r lab bsrana, eco ce aco acOae c f CRSIVECUINE. ocoesgoavene ds c a c notopatn.chey eee eee 2 ENC Carat, ours bea cence cere se 2 WGILUS taey yey tere tesa roe) lous f=. c c Heath Gusitacwer fe spore ngs e isss eve tonr cu 1 ParacalanusiparvillSeeen esi). -1 <1 { f c longistylisnnnrrreovecvoreen 1 Pontellina plumatamerrre ae = = = 2 PACHA CUS tate. s raphe a cen eay ce feowdeeie 1 Pseudocalanus minutus......... f f SPEGIOSUS a saey-nsisie ist sciatic: ete f c oy Sapphirina auronitens.......... 2 Be uchaetavacutaueeier. «secs srr f MigrOmacdlataie =. se yells 4 2 ATIEUE ITI AM aris ete vo chveic-ersirertueless are 1 2 c Scaphocalanus elongatus........ Be ae 19 Euchirella brevis. 22. 0-2-.00---- 1 1 Scolecithrixidamaet a. 3. 2... af 1 Parranula canigata...2-5- 3-9-5 a a c Wndinulacdanwimnite..-- .- 7.2 se 56 AG c ei bila 5 vane saerat issues tereceess f f The temperature fell 3° in 100 meters, the salinity and hydrogen-ion concentration remaining constant. There were 15 species at the surface, 37 in the 50-meter tow, and 44 in the 100-meter tow. Thirty-four species (56 per cent) were each confined to a single depth and 8 were present at all three depths. Although the surface tow was more than twice the length of either of the other tows, its volume was exactly the same. Corycaeus, Euchaeta, Farranula, and Oncaea were dis- tributed in all three tows, but Candacia, Oithona, and Sap- phirina appeared only in the two deeper tows. Here again the paucity of species at the surface compared with those at the other two depths indicates strong light before the tows were taken. The surface tow contained a very large number of 2 of the Farranula species. LISTS OF SPECIES BY STATIONS 15 STATION 108 May 27, 1929; 18° 26’ N, 144° 01’ E; bottom depth, 3573 m; 57 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 28.4 26.7 Sao} Density (ctp) PPE?) 23.0 DSi Salinity, o/oo 35.0 34.9 34.9 Hydrogen-ion conc. (pH) 8.25 8.25 8.23 Volume of tow, cm* 32 32 32 Length of tow, miles 0.8 1.0 ileal mAcrocalanus gibber.....-.-.-.+-.- 50 oe 2 Heterorhabdus papilliger........ 5 CACM cab. co cacaere tem Oe eo xe f # Lubbockia squillimana.......... 2 PNCCIGEUS ALMACUS. «joc seers ee ae ee 2 Wucicutiaclauisiternieeeereeceere c Salemi Giubieleg poop dauamoeeeE oe 1 ef { flawiGOnnis se icteracvere syelsrarspaeree : c Walocalanus pavOe. sae ise St 5 Sy Macrosetella gracilis............ 2 2 ae Candacia bispinosa.............. re 5 f Mecynocera clausi............. 3 longimanace rier caesar 2 Megacalanus longicornis........ 1 SIMPLER eee ayy asker relersachs cress ee 4 4 Microcalanus pusillus........... RS) RULIMCAL Meigs pcmape a,c fere laa csteersoeye te c f DY PIMACUS sere errant rots 1 1 VATIGANS Hepemp tas scrssstsicleorsctaisccta.s 2 Microsetella rosea.............. 2 bs f Canthocalanus pauper........... 3 a6 5: Neocalanus gracilis............. f f feopilia denticulata......-....+-- 1 j f GOB USHION: e:cyars eievctose stereo stapees 2 f Quadratal ne, acess: esctyscret a 5 f Oithona attenuata.............. 4 f RECA aS cig Ae Oo ae aeRO 2 pO liammi fe raters ryacen vet exer eerees 2 34 WERE oat ie Ee ee 2 f Sihoett Sole orc Maceo meet nos aonb f f BPOLY CACUS: AGTNS 2.5.01 wicieie ois eyeue » ae 2 Ae SPINILOSULIS Merete eres ee f @AWICS Ge so acme er ioetens 2; ms = @neaearconiferae. wets eee ae ae 3 CLASSEUSCUMUS jee e eseiess sete 3 c c TMOG Aye See sys, ie) s ayers cy opener ote f UCL LE tr apenas ccersiayere eae dea ae Ay 3 ae THUY P ELIE Na pene ceain Cece cco rena 3 ae ce Him babusscce.s hes tickers ees ees G WE TLUISHAINE Ping bayer ok cotta tient ONGIITS Gee tists om ae taal cree ae 1 oe a Paracalanus parvus............. 2 f f SPECIOSUSHe uta themes tect? 2 c c Phaenna spinifera.............. ne i Eucalanus attenuatus............ be 3 3 Pontellinalplumatarms sn, sees We ee 1 BrIGhaetayManinay cet ie «2 22-1 3 f Pseudocalanus minutus......... 3 f Maimanilacarinata. «<6. «2-2-1: f c Sapphirina nigromaculata....... ws ie 2 GONGINN ae yaeieps fe tees eee ee 2 ae we stellatampesers cere ain aes Sire ore 2 Gin tlkiace Boudeou ces see oes 1 f Scolecithrixsdanaesee asec asec ee 1 OSULatAMy cer. casters sete. esse f f Undinulatdarwamitieecey-)et f f Haloptilus longicornis............ 4 Again the high surface temperature fell 3° in 100 meters, and only 3 were found in all three tows. Corycaeus, Farranula, but the salinity and hydrogen-ion concentration remained and Oncaea appeared in all three tows, but Candacia, Oithona, nearly constant. Sixteen species were taken at the surface, and Sapphirina were not present at the surface. The disparity 27 in the 50-meter tow, and 43 in the 100-meter tow. Thirty- in vertical distribution is slightly less than at the previous one species (54 per cent) were each confined to a single tow _ station, but still remains quite large. HARBOR OF AprA, GUAM May 22, 1929; 14° 00’ N, 148° 00’ E; 14 species Acrocalanus gracilis.............. 2 Neocalanus tenuicornis........... 2 Paracalanusipanvlusceeee eerie cet a Barraniila gibbula. .....2.00...005- f @itbonaattentatalnyn scree 1 Memoradiscaudatas sancti 1 OSLEACAIS «, Sis ics sic nea heistele r Simi iSeeehevwaens east i ke 2, Undinulatdarwinii sce eee es f Labidocera detruncata............ f Oncaea anita seit eels r Vulgaris oxy cope hie ebo snes el octet a Mlicrosetella rosea... ......0+- eee. 1 VETITISCA er pro mrracieen ite ee 2 Although this surface tow was made in the harbor, the ocean. Evidently such littoral forms as may live around the copepods here do not differ at all from those in the open coasts of these islands do not venture far from shore. 126 STATION 109 May 29, 1929; 23° 22’ N, 144° 08’ E; bottom depth, 5252 m; 90 species COPEPODS OF LAST CRUISE OF CARNEGIE Depth of tow, m 0 50 100 Temperature, °C 27.4 23h L 19.4 Salinity, 0/00 35.0 34.9 34.8 Volume of tow, cm 32 64 128 Acartiandana ens wien reer ES c a Acrocalanus gibber....-.....2..-< f : 5 SKACHISh aoc daieie bod oe seer f f c lONgIGORNISh eh jee secs ee hee r 12 = Aetideus armatus............... 3 Galantisnminorenee apis eee f f Galocalanusipavo’...-....-.4050 > 50 4 f plumulosus... ceca se er 2, 3 Sty lines. e\ior creel deen ot 2 Gandacialbispinosay + a.o eee f 2 SIMPIER meee Wotan cheek eee f f GRUMCAC AN eh eck ard eetcis ais alee c f VATICATIS Me arate aceasta cee 2 a Canthocalanus pauper........... ue 4 Centropages calaninus........... 2 2 Clongatis.seasce cons cateercs : 2 ee Clausocalanus arcuicornis........ 2 f c PUT CAL US sey erect cies t ete, Enero r : Clytemnestra scutellata.......... is ae 4 @opiliaidenticulata. 2. 4-5.<+-- 4. f TAD iSember venation havc) a oer 3 Guadratalesrcrn-jor-nrsisva cutee st 7 f TECE AMEE Leber me ce eats, 5, sho) nens 4 5 VALT CA pies ssis cele ots tive Latte et Wy @onycaensiagalisteemniver ae acer r crassiusculuses- ec eae f a c GUIS Seer ei anos ares ae ea r HAC CUS ei cragcie.ey22t syuee uses ee 1 JETT Sree pater iees chara roman eres ye mn r lonpistyliserje rs sae suekeeteiers ore oe He f PUES hs oer icrse ees ene ese r ee en SDCCLOSUSs ertaj tee Means ores c c EY PICUS Kees eyace cei as eosin r Euaetideus giesbrechti........... 1 se Eucalanus attenuatus............ f f Clon gartus #iciac sri. seth aes eee ss 2 euchactaracutarme cm see oe ce 2 an MATING ape rpAcieie ga Srayd sieseeee es a f Euchirellavbrevisie-eesne sees. ne 2 tl arclotilan Gana teen eee eerie a c pibbula wn thee s,iomuacrae PTACIIS pian cyte es won crteress f : ROSELAT AM era eqereteisies 5 dies ere a f f Haloptilus longicornis............ ae 2 f Heterorhabdus papilliger......... ao ale f The high surface temperature fell 4° at the 50-meter depth and 4° more at the 100-meter depth; the salinity and hydro- gen-ion concentration remained almost constant. There were 20 species in the surface tow, 57 in the 50-meter tow, and 57 in the 100-meter tow. Fifty-three species (60 per cent) were each confined to a single depth and 7 were present at all three depths. The length of the three tows was almost Depth of tow, m 0 50 Density (orp) 22.6 24.1 Hydrogen-ion conc. (pH) 8.23 8.23 Length of tow, miles 1.4 15 Heterorhabdus spinifrons........ Labidocera detruncata.......... f i Lubbockia squillimana.......... Firs 3 Mucicuttarclausit..)- 21s enn HAAG OILS pypasyereyaiccaseies efereierars lONBICOrNISs. =. once dees Aue 2 Macrosetella gracilis............ f 3 OGUlataeenerr sete sacle aires here Mecynoceraiclausin. «4. 4-2 2-- a 3 Microcalanus pusillus........... Bi ie DY CUA CUS mre ee shone seen ots bw f Microsetella rosea.............. Pe f Monstrillainsentalaaseter csc is 29 Neocalanus gracilis............. LODUSEIOUS wena eeeiaie rte erate os f CENUIGOUNIS. see eiecte we feerets bys Oithonatattentiatamee ese se tele f plumiferay faeaieente ele at oratst Z Simitlis| pe eee ase tey Ns ave stato f SPIMIOSELIS eeyeieeieermeet ete f @Oithoninamanaseeeee eee oe Oncaeakconiferanaas eet as 3 GUrtats a5 coh ca eee cect r medial 2s,c%.5,ashacetereebe meres r NN eee nicio.a bot sae f a Similis).j2%:, << s ceeeere oe r tenella nae yc oe ee tore eee Venusta® .)fscee. dea aaa oe 0 c a Onchocalanus nudipes, n. sp. ... . 3 Paracalanus parvus............. tae c PY PMACUS Heres toeieey= eeeh sie = Phaenna spinifera.............. ue f Pleuromamma abdominalis..... . Re Pontellajlobiancoier erie: ae oa 20 ae Pontellina plumata............. 1 Pseudocalanus minutus......... c Sapphirina angusta............. 2 AUKOMILEHSereciss cc eis cess essceee 1 Mmetallinatecnci «caus s sc eee nigromaculatal: «....--- - = ae on 3 Stellataeetoes sis). sarees err Scolecithricella bradyi. ......... Scolecithrixidanae.......2ceees Be f Uirdinmlavcarolic.. <0 sceeee GARWHMIL ey..5,«,cys.s8, 10 oie aeeeeeeee = c exactly the same, but the 100-meter tow had twice th volume of the 50-meter tow and four times that of the surface tow. Corycaeus, Farranula, and Oncaea were distributed a all three depths; Candacia, Eucalanus, Euchaeta, and Oitho did not appear in the surface tow. A solitary specimen of on of the 5 Sapphirina species appeared at the surface, but al the others were confined to the deeper tows. The 50-meter LISTS OF SPECIES BY STATIONS tow contains one of the two records of Monstrilla inserta for the entire cruise, 2 females. Two young males of a Pontella species (probably lobtancot), whose fifth legs were not fully developed, were captured in the surface tow. Again the small 127 number of both species and specimens (except those of Far- ranula) found at the surface indicates that a strong down- ward migration of the copepods had been in progress before the towing. SraTion 110 May 31, 1929; 26° 20’ N, 144° 24’ E; bottom depth, 3036 m; 55 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 23.8 18.3 17.9 Density (orp) 23.4 25.2 BS) 8) Salinity, 0/oo 34.7 34.7 34.7 Hydrogen-ion conc. (pH) 8.18 8.18 8.14 Volume of tow, cm’ 48 48 48 Length of tow, miles 0.5 0.5 0.5 PN Gan Glan Ganae sec et-fe cya ctere.cualcrsieiers ae c f Pnircicutiaiclausuennep eer tere af 4 c Acrocalanus gracilis............. a c c ERAGON noon eanoadoncdac 3 c a Aetideus armatus...........-... Se 4 Macrosetella gracilis............ 5 43 ae CalanusiMinOnrasn ees cae see c c Mecynocera clausi............. r f DLODMN GUUS eer ere eelsaras 1 52 Megacalanus longicornis........ 1 1 Candacialbispinosa.. s-a- 3... 1 Microcalanus pygmaeus......... ir r SUMPIOXee seit cieieie ste seis s r Neocalanus gracilis............. c a Canthocalanus pauper........... : f es TOHUSUUONe ze s ee ee eee c f Clausocalanus arcuicornis........ 4 f c EENUICONMIS = alee eesti ee 2 f HUG CALUS feyarsse arote =i esse s. 2 03s 3 Oithonualsimiliseeeee eee eee 3 f f Clytemnestra scutellata.......... 2 SPiiLOSELISH 35 sros acess sel f Copiliasminabilise a. +155 sts 1 Oneaealconiteraye ss. eeeee ae 3 (COMZOUS hipaa seonceesanubos se r THLE 1a ayeyeys sy «ia sa sree, cus-epsasio yeas er f GrassisGullisnee secre raei= a= f r a MMT Ua cpersreravoucteiite eye governs a ic Lim DaGUSS > ei. eiccsacjeusts5 cies 8 3 ie NOCOPAa- escheat eee : 2» ACINCUS facies, eicvebascs, <5, scenes, 2 Venlistabiannren semis sve tensrs f a a PUUILS serene verecrsetote -5-2e ee f 2 Oithonaysimilist#eeeeeeas: - ieee mie er c f @lytemnestraiscutellatas.... 2. <<. wee = 1 Oncaea :mediateee seven e.s2< ees f es (Conycaeusicrasstusculuseeee a eeert rere c TILINLU Cas eee es ahs) = Sos scare ae as f if ACCU yeh rirsronte ie areca eee Cares seo BOOK f Similis. ecru rte eis 2. &: cate eerie ees 2 ae longistylist. (5 peeraaarisrntecat ceca o 2 Venllistas Reger ten ceicas <5. cnc 1art. ence een aers ce c c Owais eee nerir.t ace ood roe emer racine 2 Paracalanus panvilSin -- «)--- eee ere ic c DULG erent vie ror a acne rosie emer A on r PY Ga Elise tsstoye oie 5... sete ee : 3 SPECIOSUS Se tave ls rare anSyai rere are roreterare sate rato eke 2 oie Pseudocalanusminutus: .<.....hemeea c c EY PICUSE 2 aaa auaeesnescs scat raieta chars, ole RE eh r Scolecithncellasbradyi'..- ......) emer 2 Bucalanusielongatus: seen ee cece 1 te Undinulatdanwintiarn = - 1 sseetrnterte ier f f Muchaetara Cutan sy: 2c:<218 ces eteversypere nies tatele a 1 The temperature and hydrogen-ion concentration dimin- appeared at a single depth and 12 at both depths. Corycaeus ished a little at the 100-meter depth, and the salinity in- and Oncaea were more numerous in the 50-meter tow; Farran- creased. There were 24 species in the 50-meter tow and 25 ula did not appear in either tow. Probably Farranula would in the 100-meter tow. Twenty-five species (70 per cent) each have been present in the lost surface tow as at station 110. LISTS OF SPECIES BY STATIONS 129 STation 112 June 5, 1929; 33° 51’ N, 141° 15’ E; bottom depth, 3931 m; 85 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 23.2 Dilla 19.8 Density (orp) 235 24.2 25.0 Salinity, 0/oo 34.6 34.6 34.7 Hydrogen-ion conc. (pH) 8.22 8.22 8.20 Volume of tow, cm’ 96 80 80 Length of tow, miles DU 2.4 2.6 NGarbial dana Css .iysx cesses) sen es c f Mucicntia clausiie, qe a 2 : ANCrOcalanusiPID Dek. . hase ee ee a c flaviGOnniS sais steretcta easyer Ss a f PTA Cllisnentercteven rm, ac fernt-seGtieys sie ae f Macrosetella gracilis............ 3 2 JON pICOENIS eiete ysis eater Pe 2 2 Oculatan.sacomecrcine trae Ba i Aetideus armatus............... os He 3 Mecynocera clausi...........-. a a (CAIETIIS Tie) ts ooo mo ne co uoOees c a c Megacalanus longicornis........ 3 PLOPINGUUS See eels 2 Microcalanus pusillus........... : 2 WalocalanusypavO™ cc/-a-0< cme <= 5 f es DY Ginaelsaeser rena tee f 5 3 PLWMULOSUS yee etrsiele eile 1 cs 2 Microsetella rosea.............. 1 r SiyliremiShaeee seem oes si 1 1 Miracialetteratalssereeietetetet ete 1 1 Candaciajacthiopicas .. ..2 4. e% «s)- 1 Monstrilla insertas.- 4s. eee nee 59 Bas bipinnatarns cr seni es smyere 2 Neocalanus gracilis............. 2 f a ISplOOSal tae one era stev state eases © f FODUSHLON. = cc.2 chee si erersnerate ere f f GUI. coe dooms pte 5 ousones 2 4 tenuicoEniS sass 55e5 ee 1 2 c MOGVERICAN «cr cisysie chavs ss yerei sa 2 Oithonalattenuatas yee ee f 4 SIMPlEXe pass cease ess im gaan 2 plumiferapeen see ae f c EHUUCALA eres efe woes ssc was or f Ss Simlish vars c ar araameer c Canthocalanus pauper........... f f 4 SPININOStrISerse sera ele ee f Centropages calaninus........... 4 ka Oncaeaiicurtasc: 34>. soe oa 2 Clausocalanus arcuicornis........ @ ie IMEC lalaveqcteuatNet cyerssreearain cre AUKCACUS aierie.e ects Riis cis ae eos ot Sa f THUG A Heretic Pak teneaioece, ata ce c c Clytemnestra scutellata.......... i 2 SIMULIS Haran canon oes lee % f Copiliavdenticulatac... ao. < a< «<6 tenella. 3: shoscutan es eee r CTA Na bo mGone Cem eee 2 VENER oomodaoogcnsnnote c c c [KACD Oa ee ra toc CEO Ee Oeics 3 Paracalanus aculeatus.......... r Be Corycaeus crassiusculus.......... c f c PaRVSreyee toe cre aoe f c c UGC ety. aii Seeeie s ee we ees 2 Pleuromamma gracilis.......... ot 3 2 Hib DOCK ete stayersysss x alec, ese 1 Pontellina plumata............. f Me POUTLUS Sete one erie also eiens ens a f r Pseudocalanus minutus......... c c c SREGIOSUS ser trsteun soiree tess f 4 2 Rhincalanus cornutus........... ot 4 EV PICUS Manis re tsiccsovaye 5i< eertatc Ss 4 G MAGSULUIS seeeera tera ntels rex cthea eke 2 Danodes plumata, n. gen. and n. sp. 39 kas ys Sapphirina angusta............. yy Eucalanus attenuatus............ c { AUEOUItEDS )- 5s) sees ele el 3 ae 1 GEASSUS aera teacicrs eas tees 4 3 nigromaculatae meee eee 1 lon galhussine sa sce are coveveteer cies cis c f Opalinaneee-tiie yer sacle 2 2 Brichaeta, acuta’: <2, 2... 2s.c.c.d <0 sce 3 by Scolecithricella bradyi.......... 3 f TALI NAS rerayssrers ve ce ais sie aye f f Scolecithrix danae.............. c f Hatraniila!caninata). .. <<< ce a a Ono Chen. «-canccosouandsac a a a Clausocalanus arcuicornis........ c Oncaea utaseerr ree ser: 2 f Eucalanus attenuatus............ “ie f f Raracalanusspanvyus sae erie se f f GOMES oo ong ee nda cao cae f c PYPINACUS sae cee ces ea : f DIGIEGIETERI IE ras 5 Se aon eK ag 4 Pseudocalanus minutus......... f c Gaidius tenuispinus.............. : 3 Scolecithricella bradyi.......... “i f Metridiatlongar..)-i.-men. oe =o ae c c POLTECt al. aarsegs eres eiescposens: 3's a a c WUCONS cecrescrs sess Secu ee ie c The surface temperature was a little higher but fell 70 per cent in the 100 meters; both the salinity and the hydrogen- ion concentration were low, the former increasing slightly with depth, the latter decreasing. Five species were found at the surface, 11 in the 50-meter tow, and 19 in the 100- meter tow. Nine species (45 per cent) were each confined to a single tow and 2 were present in all three tows. Oithona and Oncaea were still represented by a single species each, the former abundant in all three tows. The surface tow was made up almost entirely of Oithona and Calanus finmarchicus. STATION 123 July 15, 1929; 50° 27’ N, 172° 51’ W; bottom depth, 5464 m; 16 species Depth of tow, m 0 50 100 Temperature, °C 8.1 4.4 3.0 Salinity, 0/oo 2a 32.8 33.3 Volume of tow, cm? 320 Pot BNGAT ELAN AMAG eerste, dics 6 se ects a MEGS ENS siete cir sere siete ative a f fe Bxcrocalanus gracilis. ...........: 2 falanus finmarchicus...-........ - ii 2 hy PEGLDOLEUS a. seis Se es os x f c Clausocalanus arcuicornis........ f Eucalanus elongatus............. a 3 c Megacalanus princeps............ 1 Depth of tow, m 0 50 100 Density (orp) 25.5 26.3 Diet Hydrogen-ion conc. (pH) 8.03 7.94 7.79 Length of tow, miles 0.8 1.0 50) Metridiailucenssen eae nn. c c Microsetella rosea.............. f Neocalanus robustior........... 4 2 @ithonaysimilish sacs. ees «se a a Oncaecammin taser 2 fi Paracalanus parvus............. f i Pseudocalanus minutus......... a f f Scolecithricella porrecta......... fi *Development stages. The surface temperature was still low, and fell 5° in the 100 meters; the salinity increased slightly and the hydrogen- ion concentration diminished. Five species were found at the surface, 9 in the 50-meter tow, and 13 in the 100-meter tow. Seven species (40 per cent) were each confined to a single tow and 2 were present in all tows. The 2 Calanus species were represented at the surface by development stages. No Oithona, Oncaea, or Metridia appeared at the surface. 138 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 124 July 17, 1929; 52° 19’ N, 162° 02’ W; bottom depth, 4780 m; 17 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 9.3 358) 4.0 Density (otp) 25.2 26.1 PH flew? Salinity, o/oo 32.6 Se 7/ 33.6 Hydrogen-ion conc. (pH) 8.04 8.02 7.64 Volume of tow, cm? 31 256 93 Length of tow, miles te 1.4 1S: \Acartiandander rey yertsa sererer bie roe f Megacalanus longicornis........ 1 a Fo MAM, coo cock o nd iocog ane f as 2 Metrtdianlwcensaertler ear aer a a Acrocalanisieracilis.ja. 4s sr) 2 r Neocalanus gracilis............. f 2 Galannsicnistatusneee ert iritater f f Oithonatsimilise ce -1-).-..sieeteweee a a ae finmMAaLchicus: qj. —aetesee el 4 4 a Oneaeahmimutaly car's «sie creiae f 4 II NAUGS con saonaonedosy f c c Paracalanus parvus............. f f Clausocalanus arcuicornis........ f Pseudocalanus minutus......... c f Eucalanus attenuatus............ oe a f Scolecithricella porrecta......... 2 elongatuss.sce orcs cee. ot f 2 The surface temperature was a little higher but dropped 5° in the 100 meters; the salinity was low and increased slightly with depth, and the hydrogen-ion concentration diminished. Nine species were taken at the surface, 10 in the 50-meter tow, and 13 in the 100-meter tow. Only 4 species (25 per cent) were each confined to a single tow, and 2 were present in all three tows. The surface tow contained many development stages along with the adults, but the former were so young they could not be identified with any certainty. The 50-meter tow was composed largely of Euca- lanus, Metridia, and Oithona; Metridia was also very abun- dant in the 100-meter tow, but did not appear at the surface, whereas Oithona was abundant at the surface and in the 50- meter tow. Oncaea was confined to the two deeper tows. STATION 125 July 19, 1929; 51° 58’ N, 150° 39’ W; bottom depth, 4536 m; 10 species Depth of tow, m 0 50 100 Temperature, °C 10.5 5.5 4.2 Salinity, 0/oo wT S28 32.9 Volume of tow, cm® 31 64 93 Acrocalanus gracilis............. oy f ec Calanus finmarchicus............ f 4 hy perboOreus).c 1.5 eu0a-+ sc - fe c a Clausocalanus arcuicornis........ 2 Eucalanus attenuatus............ f Depth of tow, m 0 50 100 Density (op) 25 26.1 26.6 Hydrogen-ion conc. (pH) 8.03 7.98 7.89 Length of tow, miles 1.4 1.0 it Eucalanus elongatus............ c a Metridia lucens................ 2 f Neocalanus gracilis............. f 7 Oithonatsimilisyeeen--- a. o- 2 see a a a Pseudocalanus minutus......... f f *Development stages. The surface temperature was a degree higher than at the preceding station, but fell 6° in the 100 meters. The low salinity increased a trifle, and the hydrogen-ion concentration diminished. Three species were taken at the surface, 1 of them represented entirely by development stages; 8 species were taken in the 50-meter tow, and 7 in the 100-meter tow. Only 4 species (40 per cent) were each confined to a single tow, and 2 were present in all three tows. Oithona was abun- dant in all three tows, but on the other hand, Oncaea does not appear in any of them. LISTS OF SPECIES BY STATIONS 139 2) STATION 126 July 21, 1929; 48° 05’ N, 142° 56’ W; bottom depth, 4382 m; 13 species Depth of tow, m 0 50 100 Temperature, °C ley etl 6.4 Salinity, 0/oo 32.6 32.6 SQ Volume of tow, cm’ 62 ae Wetideusianmatus... 2 5c. csa. 0. 1s ee e: 1 Oalanvisicristatlis mern ace ee, eae 4 1 te finimarchiGhstrcearrer tae f 8 f iy DEG DOEUSE:. 2 ayerctes «cts 0) c 3 c Eucalanus elongatus............. 3 NCiGuhia HavicOnnises-+ <6 . 1 Macrosetella gracilis............. 2 The surface temperature was again 1° higher than at the preceding station, and fell nearly 5° in the 100 meters; the salinity remained practically the same, and the hydrogen-ion concentration diminished a little. Three species were taken 50 100 26.1 8.01 Depth of tow, m Density (otp) 24.9 Hydrogen-ion conc. (pH) 8.09 Length of tow, miles 1.9 Microsetella rosea.............. Oithonatsimiliseeepee ee neo ee SPININOSEMISEEe yeti clone «seek Oncaecamminitasereeterieen acer > PRmNHNa ms at the surface, 2 in the 50-meter tow, and 12 in the 100-meter tow. Ten species (77 per cent) were each confined to a single tow and only 1 appeared in all three tows. Oncaea appeared again, but with Oithona was found only at 100 meters. STATION 127 July 23, 1929; 44° 16’ N, 137° 37’ W; bottom depth, 4026 m; 14 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C ils} 58) 10.5 8.2 Density (ctp) 24.5 2563 25.9 Salinity, 0/oo 32.6 32.7 2a Hydrogen-ion conc. (pH) 8.12 8.09 8.00 Volume of tow, cm# 64 128 128 Length of tow, miles 1.9 Bil Dee, mcracalanusyeracilis... wa... bess « c : Neocalanus gracilis............. ae f a Sealanusicristatliseeyee ces oe ose e- an f EENUICONISs meee serrate : a RAMEN ATG HYGUS Seceevareetetere sty se ays a a Oithonarsimilisaeeen cere ee f f a NY PET DOLEUS] 6-625 cece eens 6 Be a c SPUUTOSELISH sass sees: = c Clausocalanus arcuicornis........ : 3 Oithoninasaana see eereien f Eucalanus attenuatus............ f f c Paracalanus parvus............. 4 GHASSUSA ry cisatereisais ave eoaus Gastetes Sy3 ae 1 Pseudocalanus minutus......... The surface temperature was somewhat higher and fell about 5° in the 100 meters; the salinity was low and increased a trifle, and the hydrogen-ion concentration diminished. Six species were found at the surface, 6 in the 50-meter tow, and 10 in the 100-meter tow. Nine species (64 per cent) were each confined to a single tow and 3 were present in all three tows. The volumes of the two deeper tows were the same and each was twice that of the surface tow. There were many development stages of Calanus finmarchicus with the adults at the surface. COPEPODS OF LAST CRUISE OF CARNEGIE 140 STATION 128 July 25, 1929; 40° 37’ N, 132° 23’ W; bottom depth, 3806 m; 7 species Depth of tow, m__ 0 50 Depth of tow, m 0 50 Temperature, °C 16.4 wile i Density (orp) 24.1 25.4 Salinity, o/oo S20 33.0 Hydrogen-ion concentration (pH) 8.12 8.11 Volume of tow, cm® 48 96 Length of tow, miles 1.0 1.0 Acrocalanusigna ciliser puter serene ie eres c f Oitshouarsiumilisn.-\.,5checre aoe eee f a Clausocalanus arcuicornis................. Raracalanus parvus.«. ur e.jeeeceers eer c 2 Glytemnestrairostrataee cs -aeeeee a 2 Esendacalanus minutuse 4. ee seer eae INeocalanusreracilisnem eerie einieaer Sc f The temperature was moderate at the surface and fell nearly 5° at the 50-meter level; the salinity and hydrogen-ion concentration scarcely changed. Five species were captured at the surface and 5 in the 50-meter tow. Four species (57 per cent) were each confined to one tow and 3 appeared in STATION 130 September 4, 1929; 37° 05’ N, 123° 43’ W; bottom depth, 3188 m; 45 species both tows. The length of the two tows was exactly the same, but the volume of the 50-meter tow was twice that of the surface tow. Clausocalanus and Pseudocalanus made up the bulk of the surface tow and Oithona that of the 50-meter tow. Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 16.2 11.7 8.8 Density (op) 24.4 25.6 26.6 Salinity, o/oo 33.4 33.4 Soe Hydrogen-ion conc. (pH) 8.34 8.26 8.06 Volume of tow, cm’ 224 192 190 Length of tow, miles 0.7 0.9 0.9 INGarbiancdanae snr ferences 1 Eucicutialilaviconnisee ti ietrett f Acrocalanuisieracilisanr semen f longicornis! .4--- are 1 TMMONAGAUSH yay 4 emissary ees f Macrosetella gracilis............ ae c f Galanus/finmarchicus: ..:.......- a ae f Metridia brevicauda............ f hy PexvOreus= aes eee be 2 lucens'..s hc. o-en eee eemeete c PLO PMGUUS yore ee teeters ever a < 1 Microcalanus pygmaeus......... 1 Clausocalanus arcuicornis........ 7 f Microsetella norvegica.......... a fran 2 Gonycaeusanglicuss.- cee «2 r FOSEA!:.5. ciate ccca epee uapenmuerstt steve cls as 1 Labidocera detruncata.......... f Lubbockia squillimana.......... oe 1 ie ucicutialclaustmeryeyverters ae 1 a HEC onaenacach sonneE 2 Macrosetella gracilis............ c c f oculata 25 926..:2< suds Rye clereisnais 3 1 Mecynoceraclausi=. a. serene f c Microcalanus pusillus........... f r PYPIMACUS Heys cis) eee aD f r Microsetella rosea.............. c c G INeocalantsreracilise. sc eerae f c a CEMULCOLDIS): ase ae Cc c c Oithonaypliumiufera,y..- ser f a Simmilisteeges.cieucrcere en eaee vane c c Sioa ganaosanodengdc f f @ithoninamanaeeees eae f Oncaealminutal. 7... 4+ eee a0 a c tenella: .s)5 0 sterner eae 1 VEMUStaM severe ctens eloped c a a Paracalanus! parvilsue. «erent c c c PYSMACUS acy. race ace eT ine f r Pontellina plumata............. 1 Pseudocalanus minutus......... 0 c c Sapphirina auronitens........... 2 2 metallina: 4 cancer la c MigromaGulatalmter es) <1 56 2 Fic Scolecithricella bradyi.......... ae ne 3 Wndinulatdarwamtinenwrt rite ser oh f The temperature was high at the surface and fell 4° in 100 meters; the salinity and hydrogen-ion concentration changed very little. Twenty-six species were taken at the surface, 44 in the 50-meter tow, and 36 in the 100-meter tow. Twenty-eight species (45 per cent) were each confined to a single tow and 10 were present in all three tows. Corycaeus, Oithona, and Oncaea were each distributed at all three depths, but Farranula did not appear in the 100-meter tow. The three tows were of practically the same length, but the volume of the surface tow was as large as the combined volumes of the other two. Oithona plumifera was especially abundant in the 50-meter tow. LISTS OF SPECIES BY STATIONS 149 SraTion 140 October 3, 1929; 23° 26’ N, 159° 27’ W; bottom depth, 4762 m; 46 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 26.9 26.9 255 Density (orp) 22.8 23.0 23.6 Salinity, 0/oo 35.0 35.0 35.0 Hydrogen-ion conc. (pH) 8.42 8.39 8.34 Volume of tow, cm# 96 64 32 Length of tow, miles il il Boil IANGAGbIaIGAnaCan occ c ss oe ses cur f f c Rarranuilasostratar arene ~ oe f Acrocalanus'gibber. . 2). 0.2%. ee r Labidocera detruncata.......... f As ORAGLISMME Eine afer tester oie f c f ucicuviarclausiteey eer etre ae 1 OMPAGORU IS afernc eyeteiey e-rsvel= ie 2k r Macrosetella gracilis............ om 3 f (Gallanlistmin OTe... or ives etic aes ae f f Mecynoceratclausicmes sire) 2 ; f PLOPINGUUS Netelsomyever-oit = Wess ts Microsetellairoseazer nc este see 1 Buchirellavcurticatdawe ae eieereneeeeiae ele 1 Pseudocalanusimmutusa- eer sees: reece c Barranulaicarinavalsts1-reaiciciseis« are eerste c Sapphininalaunouitensespeeyec ele eleieeeie 3 ib lar peter. wise. snraparsis 2e hs eens ete ese { an Nigvomacnlatan mee sere sicjoe. = oes a 2 TOSERAL Aap itch gees cre ocasireszervensh essen raat es A eens =a f Scolecithnixsdana eter crate nm ve ae iicieres ete abidocerasdetnuncatalyc sere ie aes ie ane Windinulaydatwin teers at cers rere Be c The temperature was high at the surface and dropped 1° tows. Although shorter than the surface tow, the 50-meter at the 50-meter level; the salinity and hydrogen-ion con- tow had a volume 50 per cent larger. Corycaeus, Farranula, centration were practically the same at both depths. Twenty- Ozthona, and Oncaea each appeared in both tows, but Can- seven species were taken at the surface and 40 in the 50- dacia and Euchaeta were not present in the surface tow. meter tow. Forty-five species (80 per cent) each appeared in Farranula carinata was especially abundant in the surface one tow and not in the other, and 11 were present in both — tow. LISTS OF SPECIES BY STATIONS 151 STATION 142 October 7, 1929; 32° 42’ N, 160° 44’ W; bottom depth, 5787 m; 58 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 24.0 21.8 16.5 Density (otp) 235 24.3 25.6 Salinity, 0/oo 34.8 34.7 34.4 Hydrogen-ion conc. (pH) 8.33 8.30 8.27 Volume of tow, cm* 48 32 48 Length of tow, miles 0.8 0.8 0.8 A@aidilerGEmrO. co comand ooo sono ae f Labidocera detruncata.......... a r f AGrocalanuUsigracilise . . csv. ee f ubbockiaaculeatas............ r LON GICORMIS Heme toeidettaein © 2 oe a Squullimmananget etree) false: f Calantisiminone. ca. easeesn. ness 2 a c ucicutianclatisiieeeeeer etek ee 1 f Galocalanusspavo: :.. 2s. 2s-:6: ae r f Macrosetella gracilis............ 2 Shy MremiShycpyxcocicercieemcras Sis r 3 OcUlatamttereaenf-tiers cere. < ciate 1 Gandaciasaethiopicay.ca.ccrie: 2. = 1 Mecynocera clausi............. Pa a c Tile ooenanosponondodad 1 f f Microcalanus pusillus........... 3 Canthocalanus pauper........... at 1 a PY SMACUS Hom perytee res)oe- f Centropages calaninus........... 3 Microsetella rosea.............. 5 1 f Clausocalanus arcuicornis........ c f c Neocalanus gracilis............. 2 a c ALINCALLIS MeN Mate pee yeti sccroustay classe f LODUStHOteepyrervsese terre eye eves f Clytemnestra rostrata........... c ECU COLMIS Reet en ere ae a c SGUtellatalecrea cies cyanate: a 1 f Oithonayplumifera eee ee f (Coy MCACNS Can osoonenee Gonees 2 Sheblhice. es caren to nce come in c a CRESUECMIE GaoacoodoosuoGe ye 5 f @niecaearcuntarsy rade rorcrrcnecretey=ten.« f Iii OAS ooawuee poe Goes eoe te r : MINE tae peers vera rseeeey rs iayot sy lee f ae On giStylISAe Meteracl-ttetmccisese: Ae ote c TULA eseyster = erate vaveloc 2 a RODUSEUS fctaterexs cvevayays avayeuarstss ye ane 2 NGC ein 5 Sede ood Me rere 3 a SPECIOSUS «icvss.845) s,s cnt sepsis aves ie f Pachosspuncta tumeysny.) tere -taeete= 2 Ey PIGUSH Pua wctoxcusicy star vsieer ele se ae ie Paracalanus parvus............. a c a Eucalanus attenuatus............ sig 1 2 Dy.GiMa Cusme acres ye. e) Ss: f uchaeta marina cry. lic. s. excrayo «he 3 Pontellina plumata............. oe Barraniila icarinatals «== .-c-<5 = 41> a c a Pseudocalanus minutus......... c c Cc or yy ullen eye ge rece iter ates: ane) axenditsevaes f Sapphirina auronitens.......... 3 ws ROStratabepyeleve nsrolne cies sare ab f metallinateyers cessecrs ctei< 1. <:o:-1 f Haloptilus acutifrons............ Scolectthrindanaeya... s)4a6 0 1 f lonpicornish .necch. sce hcl ae 1 f Wndinulardanwintieeeees 24... f Labidocera acutifrons............ 2 Wettonareranulosalase: sae. ls 2 The temperature was high at the surface and dropped 7°5 in the 100 meters; the salinity and hydrogen-ion concentra- tion both diminished slightly. Sixteen species were found at the surface, 26 in the 50-meter tow, and 47 in the 100-meter tow. Thirty-six species (62 per cent) were each confined to a single tow and 8 were present in all three tows. Farranula was found at all three depths, but only a single species each of Corycaeus and Oncaea and none of Oithona was present in the surface tow. Labidocera detruncata was especially abundant at the surface, adults as well as many development stages. The presence of this species in all three tows is worthy of note as it is usually confined to the surface. 152 COPEPODS OF LAST CRUISE OF CARNEGIE STATION 143 October 9, 1929; 34° 06’ N, 157° 09’ W; bottom depth, 5841 m; 33 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 22,4: 19.0 13.8 Density (op) 23.6 24.6 26.0 Salinity, o/oo 34.3 SAe2 34.1 Hydrogen-ion conc. (pH) 8.30 8.30 8.28 Volume of tow, cm* 32 32 32 Length of tow, miles 1.4 1.0 lat Acartiandanaess ans a-5..+-.- c ee x Microcalanus pygmaeus......... r f r Gata tevecyterpae a averstteuvterns tes He we 19 Microsetella norvegica.......... c MOV GG CA eens) aisha nickels eck stcnckaye f GOSCA ete se teetdess soca ska see tee H a Simplexeryemoereate vase eine cre f a a Miraciavefteratase-.-). 4. 7-4 see r Canthocalanus pauper........... r c a Neocalanus gracilis..........-:- c c a Centropages calaninus........... 1 f LODUSGOLAP Reese cere is r r Clon gatusireaslysseiers ences 3 ir EEMUMIGOGMIS Hy cei se) ele c wc c VIG LACCUS tert super alss corieussy eo) 3 Oithonayplumiuferas...-..-4-- -se i c c Clausocalanus arcuicornis........ a a a SimlliShyerweget eye Sevtiso mAs sronroe a 3 a MUI GAGUS sete aredenaie, ec suere shave apes as a a Orthoninagnanaleeere eee c Clytemnestra rostrata........... r OMCACEN CI. Dancdcdneedodcs oc 3 = ar Scuitellaitalrecnciyeisnsreraers eteutts ne te 1 TULUM CA eres reide oe easel eye ioe a a c Copiliaydenticulata. 25-55-52. r r ie TLO EO Dea ere eee el csp, sete eteye r OREO HEM Soko oer REE ae 1 r VOMIT ccey an ono eOo De oo c a a a Corycaeus andrewsi.............. r Paracalanus aculeatus.......... a a Grassimusculllsmeeas smialocaeae c f prinnGacac soo cemeoneuoedcs f c a HAGCCUS eine -Qarevsre uahsisve- + Sees 2 Pennella sp., copepodid......... 1 MAIGUS 7 gate See os en eecerste aterecur asa 4 Pontellancristatae es ee sere r RON pasty lism eects ecoyapers «efeitos 2 EBontellina plumata.....-.25-s f r r PAGINGUS sesiaee vrotscs ones oh: Sonteseyins 0 2 Pseudocalanus minutus......... we ae a SPECLOSUS irate n= vite se s.deces, es a f a Rhincalanus nasutus............ r Eucalanus attenuatus............ r c ote Sapphirina auronitens........... r A ClONSALIIGHME Ere eerste r c c Teta Linares Rene f Biichactaya Cutan ah ane ae oe c f nigromaculatal.... sel r 1 r AINA LIMA ep eetayers fs /ecfeasss fo.m.c) scacesate a a a Opalingd 3.6 aa ee ee 1 Brchirella) brevish...--i00-< s+ + << c a scolecithrixdanae see eee i a a GUAieMC hs Ascooooscons soos c c Wricinulatcar.o lisse eee ere f aLrauitalcaninata seem elec a c a danwintiteseeeene eee eer ie a a The temperature was high at the surface and fell only 0°5 in the 100 meters; the salinity and hydrogen-ion con- centration also remained practically unchanged. Thirty-four species were captured at the surface, 46 in the 50-meter tow, and 52 in the 100-meter tow. Thirty-three species (43 per cent) were each confined to a single depth and 16 were present at all three depths. Candacia, Corycaeus, Farranula, Oithona, and Oncaea were present in each of the tows and quite evenly distributed. The 100-meter tow contains the only records for Candacia catula and Pennella during the entire cruise. The latter was in the free-swimming copepodid stage and the species could not be determined. COPEPODS OF LAST CRUISE OF CARNEGIE STATION 156 November 4, 1929; 3° 01’ N, 149° 46’ W; bottom depth, 4953 m; 78 species 50 27.0 35.0 32 100 26.3 35.0 128 Depth of tow, m 0 Temperature, °C ZiieO Salinity, o/oo 35.0 Volume of tow, cm’ 48 Ncanpiandanactmnpet rete eerie ao c a longineniste errr ae ie Wcrocalanus cibbemsenecmenn eres 5 IP TAGCHISS. eet wha staty oe Mare teahe MOMACHUS Eyer eens es ete eae Calocalanusipavonncee emanate f plumulosus styliremisy j..\: css see ss > r Candaciallbispimosaneiaree ene se r MOGVEPICAY ici sie eles s steers oats ae ac f pachydactylaeeen-ssicere eee. f SIMPLER pce rere cetete revere oles sete a r a Canthocalanus pauper........... c f Centropages calaninus........... es a r Clongatusnin © sere mtecrire ere ests bg r r ViGlACeUSh ac cece Screen oe r Clausocalanus arcuicornis........ f a RUE CAEUS meine cto skcrets te etter C@lytemnestra rostrata..........-. scutellatamaemurtccre aoe Gopiliardenticulatasee | -ee - a r Guadratan eter t.cm terns ct a r WALK CAN crnce Neves ea eatece tena aa Se r = VeaWhashieh int & AAA Pp: 3 lor p cot i= nn AA JOU Nhe orne cools oom cacbome GFODUSEUS Bares, seeyereree deena cs areas ae 2 SPECIOSUS EERE 2) Dysgamus atlanticus............ Eucalanus attenuatus............ ae r elongatiist wer strict Euchaetal marina.) sae. see Enchirellaibreviss.ersenicieect (CMAR ANC Bisntnnomonaphon opine Rarranulaycaninataemnaer teens a POOP PP EP : Q Pp >a fo : The temperature was high at the surface and fell 1° in the 100 meters; the salinity and hydrogen-ion concentration remained almost constant. Twenty-four species were taken at the surface, 45 in the 50-meter tow, and 56 in the 100- meter tow. Thirty-nine species (50 per cent) were each con- Depth of tow, m 0 50 100 Density (op) 2255) 23.0 23.4 Hydrogen-ion conc. (pH) 8.34 8.35 8.33 Length of tow, m 1.6 5) eel Harranulareibbulaneeeeieereer Ns f WOStTatar.ccmiyarue ers: eyes ts f ae r Heterorhabdus spinifrons........ a [F F Wucicutiaclausis.seseeeee eee Ae ays f flawiGOniliS wae «eee aro ae st r Macrosetella gracilis............ r ye Mecynocera clausi............. r G Megacalanus longicornis........ r a Microcalanus pygmaeus......... c r Microsetella norvegica.......... f oe FOSCA yar perso ster saarecesarislereters c a Miraciarettcrataaeense eae ce i Neocalanus gracilis............. c jo) 001215) (0) panic Hicho CAG Seo Once r CEMUICOLHISMe ener eran ee G c Oithona plumifera.............- = f c SQCIZED Scie cere cere ale ieracis 2 SIMMULISK 2 ois, se teueeera ate erence ao a a SPINILOStLicar Seen er f @ithoninamana seers ir c Oncaea curtal Sx. sey cece. : r Soul -\a) eerie oo on cea oor r ive MINUtA cee eet a c c HOO) ERS s.cin Oooo A Qa dee 3 VenUStalz ci ce teeter te aa 3 f a a Paracalanus aculeatus.......... c c DARVUS = crpecleerey ste st ase teehee ae c c Pontellajicristatameaeereiree = one r Pontellina plumata............. r ae r Pseudocalanus minutus......... c Sapphirina auronitens........... ie r ste MAMIE, oouduasobopeuede™ 1 it Nigromaculatal. 4. a0 ee r r r Opal itaraetere cece ciiccseeousecneneaaeretes a Br ie Scolecithricella auropecten....... r ALPACA evar /-) rae ciers sees f r Scolecithrix danae.............. @ a Uindimulaycarolinc =. 1n eee ie f Garwinit:.... seen aces (e a fined to a single depth and 8 were present at all three depths. Corycaeus, Farranula, Oithona, and Oncaea were found in each tow, but Candacia only in the 100-meter tow, which also con- tained the only record for Dysgamus atlanticus, a parasitic form that sometimes leaves its host and swims about freely. LISTS OF SPECIES BY STATIONS 165 STATION 157 November 6, 1929; 1° 48’ S, 152° 22’ W; bottom depth, 4693 m; 71 species Depth of tow, m 0 50 100 Depth of tow, m 0 50 100 Temperature, °C 27.0 27.0 26.8 Density (op) 22.8 Phos il 23.5 Salinity, 0/oo 35.2 S47) 35.4 Hydrogen-ion conc. (pH) 8.27 8.32 8.30 Volume of tow, cm? 32 80 64 Length of tow, miles 0.4 0.9 0.9 BerCartiadandes: ncn safe cyects ewes care c a Haloptilusiacutifrons. .......... ae So 2 LOngiremMiSy occ ciers cc S.cGjens ess bs Ae f longiconmisemter imei s1e 1.1: a a5 r Wcrocalanus gibber.............. c Labidocera detruncata.......... r ae IPTAGINS pas ataria crane, fyexsceyete ase c Macrosetella gracilis............ 1 MONACHA US Hye tevetkss shaia,e eevee sie f c Oculataryem reyes sieraic ects 1 Aegisthus spinulosus............. 1 r Mecynocerajclausi./s 4.2... .--- r ar Bealanus minor. -.-..-.-.-....... ae oe c Megacalanus longicornis........ r r DPROPINGUUSi eae ascii c As Microcalanus pygmaeus......... c c ic (€alocalanus pavo.........-.-.:: a a r Microsetella norvegica.......... r c Styne mis teyeyeceioc (2) acite cae r r IRONS Nate bee Atencio cree, CSTR a a @eandacia bispinosa.............. r a Miraciavefieratase:-eeetnse sce. -. c r a SITMPIONPR Erode toe oss ene sie. Ii a C Neocalanus gracilis............. c a ‘Canthocalanus pauper........... f c RODUSEIONsyaw ees a ctoreday-t eres he 1 ae ‘Centropages calaninus........... r r a: HENUWICORMISt. wes sa seree ee c a c | QONEHICS 5 on Cos es Eee oe c c r @Oithonatplumiferat cn)... f f 5 AUG CabUsees wert tc soen ieee cca r r se LODUSLAR waste eases exon cartiec oe Si r ‘Clausocalanus arcuicornis........ a a c SEGIC OLS entae cos ote aeynira'< bathe nf of r Copilia Genticulatalncs.--sce2s f r SLOTS 4 enter cp nce Ste a a a Quadratascectoncteriysen cies f r SPINILOSERS enue erane etl f r MSorycaeus clausi................ 2 23 Oithoninasnanamema eerie f IGLASSIUSCUIUSE reteleyerteiere eeu: < f c C @ncdeatmediavyy nse sey-cae eee a a f GIN TU GE oc coo Or eee CO Ors 3 HILAL LANG ererctchevs ete pexcilore sete c c NURSES 7 4.ats bro bree ote tree e : fs 3 tenellan eS hcnsas ee eee r longisty lisa: = ejetiecnete.cc.2 ae bis 3 NOPUG Hips aomen oon momen a a a Ovaliswmebchacients sears oo cess: 3 1 Paracalanus aculeatus.......... c an SPEGIOSUSi io c.ccesieyeccsine sel > a a a DAT US irons escent Attsnes Gr eperer: c a c TSDC Sag prot cited Maree achat So se r Pontellina® plumatay. +... .e- r r r ‘Eucalanus attenuatus............ c ic r Pseudocalanus minutus......... os a c elon gatLseee set tee te cse poe he sis f c ag Rhincalanus cornutus........... r Seuchacta marina..........+:.--+- c c TASLIEUS yep ecterevsreyei secre aes r menichirella brevis... .< «1262 «essitee esse be 3 ae SImilisneep eee ccc - a r limbatustcehcte sac rmkrs ere ae ae r temell aeemepeeetebee tentetay ee! o= = i : hab bookie syst yeryeetegsre hereray 1 a a: MEMLUSEA eetersedeteistels cl cleie/e)= a c a DEMS oo guoonen gomododas F r ParacalanusyparVUse rience = = =: a f c SPEClIOSUS mera Prachi aaterche ask c a Pleuromamma gracilis.......... a aD r (HMOs gacsgonoomocdoodo a r f f Pontellina plumata............. 3 r ie Danodes plumata, n. gen. and n. sp. 19 Pseudocalanus minutus......... c Eucalanus attenuatus............ aie r f Sapphirina auronitens........... 2 r elonpatustesyace coerce ee tae a5 a r migromaculata...........--. Tr Buchaeta maracas = etnias c a a Scolecithricella abyssalis........ c Buchirellaybrevisseseicce ce cee r r r Scolecithrix danae.............. oa a f GULHGAUGa. 5 sss tcislcros ole ier ste r Rs r Windinwlaycaroliis. ic = <1) ceserierrs r Barrantilavearinatay. -1\4e-c = = a c c Ganwintieh.. ./tyarsee)-0 Serer c c c The temperature was high at the surface and did not change 17 were present at all three levels. Candacia, Corycaeus, at all in the 100 meters; the salinity and hydrogen-ion Farranula, and Oncaea were all found in each of the tows, concentration also remained practically unchanged. Thirty- and 4 of the 5 species of Candacia appeared at the surface, seven species were captured at the surface, 32 in the 50- an exceptional distribution. The 100-meter tow contained meter tow, and 59 in the 100-meter tow. Thirty-seven 1 specimen of the new genus and species Danodes plumata, also species (50 per cent) were each confined to a single level and 1 rather rare species of Scolecithricella and 1 of Amallothrix. DISCUSSION OF SPECIES (Alphabetically Arranged) Since this paper deals chiefly with the geographical and vertical distribution of the copepod species, they are here arranged for convenient reference in alphabetical order without reference to their systematic relationships. The number of new species is small considering the thousands of specimens examined, but is all that could be expected in tows made so near the surface of the ocean. Attention has been concentrated particularly on dis- covering the reactions of a long list of known species of copepods to temperature, salinity, hydrogen-ion concen- tration, and light in their native habitat. A surprising amount of information along these lines may be extracted from the station records above, and this has been pre- sented according to species in the discussion that follows. [|The bibliographic references to the original publica- tion of each species given in this paper did not appear in the original manuscript submitted to the Institution. They have been assembled and verified by Miss Lucile McCain, of the Division of Marine Invertebrates, U. S. National “Museum. In the case of species amplified by Dana and ~Giesbrecht in their larger monographs (in 1853-1855 and 1892 respectively), reference to these particular works is also’ made, as well as to the very brief original descrip- tions.—Ep. | Genus ACARTIA Dana, 1846 Acartia clausii Giesbrecht [Acartia clausii Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 25, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 508, 522, pl. 30, figs. 2, 6, 9, 13-15, 17, 28, 36, 37; pl. 31, figs. 36, 37; pl. 42, fig. 32; pl. 43, figs. 3, 5, 14, 1892.] Found at only four scattered stations in the central and northern Pacific, but more common in the northern Atlantic. It was taken in 7 nocturnal and 7 diurnal surface tows, 4 50-meter tows, and 5 100-meter tows. All the Carnegie speci- mens taken in northern latitudes were at the surface or in the 50-meter tows; those found in the tropics were in the two deeper tows. It is worthy of note that this species was not recorded in the Challenger or the Siboga expedition, nor from any Pacific station in Sars’ (1925) “Bathypelagic cope- pods.” It would seem, therefore, to be more or less indifferent or possibly somewhat positive to the weaker light of northern regions, but becomes negative to the strong light of the tropics. Acartia danae Giesbrecht [Acartia danae Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 26, 1889; Fauna und Flora des Golfes yon Neapel, vol. 19, pp. 508, 522, pl. 30, figs. 1, 23; pl. 43, fig. 8, 1892.] 169 Not obtained at any of the Atlantic localities, but widely distributed and often very abundant in the Pacific. With minor exceptions there are two notable gaps in its dispersion in the latter ocean, one from station 48 to 61 in the south- eastern region and the other from station 116 to 131 in the region north of 40° parallel of latitude. It was present in 19 nocturnal and 46 diurnal surface tows, 77 50-meter tows, and 60 100-meter tows, and in the vertical tow from 1000 meters at station 64. This would indicate, as in the previous species, more or less indifference to ordinary light with a definite downward movement when the light becomes stronger. The species is readily recognized by the strong spines at the posterior corners of the fifth thoracic segment. Acartia longiremis (Lilljeborg) [Dias longiremis Lilljeborg, De crustaceis ex ordinibus tribus: Cladocera, Ostracoda et Copepoda, in Scania occurrentibus, p. 181, pl. 24, 1853.] Present at nearly every locality in the Sargasso and Carib- bean regions, but confined to a few stations in the Pacific, north of the Samoan Islands. It was found in 1 nocturnal and 10 diurnal surface tows, 11 50-meter tows, and 14 100-meter tows. So far as the present vertical distribution indicates, it is practically indifferent to light. Sars (1903, p. 149) stated that this species sometimes occurs in great numbers along the Norwegian coast, but no trace of such gregarious com- munities was found in the present plankton. Acartia negligens Dana [Acartia negligens Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 26, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1121, 1853; pl. 79, fig. 3a-c, 1855.] Not present in the Atlantic plankton; in the Pacific it was well distributed in the eastern and southeastern parts but everywhere else extremely straggling, with an appearance at one or two consecutive localities and long intermediate stretches of total absence from the plankton. It was taken in 16 nocturnal and 25 diurnal surface tows, 27 50-meter tows, and 27 1o0-meter tows; also in the vertical tow from 1000 meters, station 64. Such a vertical distribution indicates even more indifference to light than in any of the preceding species, and this conclusion is strengthened by the fact that the species was often found equally distributed in all three tows at the same time. Genus ACROCALANUS Giesbrecht, 1888 This genus was not found in the Atlantic plankton ob- tained by the Carnegie, but the species /ongicornis has been reported from the North Atlantic. Four species of the genus were found quite abundantly in the Pacific, one or more occurring in every region, so that the genus cannot be desig- 170 nated as belonging to any particular zone. The species are all very small, with both fifth legs lacking in the female and the right one in the male. /00 DEPTH IN METERS Cuart 1. Daytime vertical distribution of species of Acro- calanus: (1) gibber, (2) gracilis, (3) longicornts, (4) monachus. The four species were well distributed at all three depths. Three of them were more abundant in the 50-meter tow than in either of the other tows, but the fourth was found at the surface not only more often but also in greater abundance. Acrocalanus gibber Giesbrecht [Acrocalanus gibber Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 332, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 171, 175, pl. 6, fig. 32, 1892.] Each species of the genus shows very prominent gaps in its distribution, those for the present species including stations 44 to 54, 59 to 63, 68 to 91, 117 to 131, all inclusive. It was found in g nocturnal and 29 diurnal surface tows, 25 50- meter tows, and 22 roo-meter tows. It is thus apparently in- different to light, and this conclusion is strengthened by the fact that it is found frequently at the surface, at any two of the depths, or even at all three. The surface records not only are more numerous than those from the other tows, but also indicate a larger number of specimens. Acrocalanus gracilis Giesbrecht [Acrocalanus gracilis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 332, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 171, 175, pl. 6, fig. 27, 1892.] More widely distributed than the preceding species, but not found from stations 71 to 77 inclusive, with a few other gaps of one or two localities only. This species was present in 31 nocturnal and 75 diurnal surface tows, 78 50-meter tows, and 75 100-meter tows, and in the vertical tow from 1000 meters, station 64. In the daytime, therefore, the vertical distribution at the three depths was exceptionally even, but the abundance records in the surface tows were slightly higher than the others. Acrocalanus longicornis Giesbrecht [Acrocalanus longicornis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 332, 1888; Fauna und Flora des Golfes yon Neapel, vol. 19, pp. 171, 175, pl. 6, figs. 25, 33; pl. ro, figs. 34, 36, 39, 1892.] The gaps in the distribution of this species extend from stations 42 to 51, 55 to 65, 67 to 87, and r14 to 134, inclusive. This species was taken in 1 nocturnal and rg diurnal surface tows, 26 50-meter tows, and 13 100-meter tows. Here, then, the 50-meter tow definitely surpasses either of the others, and there is a marked contrast between the 1 nocturnal surface COPEPODS OF LAST CRUISE OF CARNEGIE tow and the 31 for the previous species. This species has been recorded from the Atlantic and Indian oceans and the Red Sea as well as from the Pacific, and its absence from the North Atlantic in the present plankton is noteworthy. Acrocalanus monachus Giesbrecht [Acrocalanus monachus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 333, 1888; Fauna und Flora des Golfes yon Neapel, vol. 19, pp. 171, 175, pl. 6, figs. 26, 31; pl. 10, fig. 38, 1892.] From station 36 to 86 this species was present only in soli- tary localities; from 88 to 107 it was present at every station except two, and from 108 to 157 it was again found only at isolated stations, making it the least common of the four species. The forehead is very high, projects forward, and is acutely rounded at the anterior corner, which in the present material was nearly always white, facilitating the identifica- tion of the species. It was found in 2 nocturnal and 11 diurnal surface tows, 32 50-meter tows, and 17 roo-meter tows. Here again a majority of the specimens manifested a definite preference for the 50-meter tow. Genus AEGISTHUS Giesbrecht, 1891 Aegisthus spinulosus Farran [Aegisthus spinulosus Farran, Ann. Rept. Fisheries, Ireland, 1902-03, pt. 2, app. 2, pp. 46, 47, pl. 12, figs. 8-14; pl. 13, figs. 1-4, 1905.| Found only at 9 localities in the eastern Pacific and at 1 station north of the Samoan Islands. It was captured in 3 nocturnal and 3 diurnal surface tows, 2 50-meter tows, and 2 100-meter tows. These meager records do not warrant any general conclusion except the negative one that this species does not always migrate downward in the daytime. Genus AETIDEUS Brady, 1883 Aetideus armatus (Boeck) [Pseudocalanus armatus Boeck, Forhandl. Vidensk. Selsk. Christiania, vol. 14, p. 38, 1872.] Well distributed in the Sargasso and Caribbean regions, but quite gregarious in the Pacific and limited to a few localities in each of four regions: the eastern tropical, north of the Samoan Islands, north of the Caroline Islands, and north of the Hawaiian Islands. It was taken in 1 nocturnal surface tow, 10 50-meter tows, and 41 100-meter tows, but was nowhere abundant, more than half the records being expressed in numerals. Thus it is definitely negative to light but comes to the surface sometimes during the night. Genus AMALLOPHORA T. Scott, 1894 Amallophora typica T. Scott (Figure 1) [Amallophora typica T. Scott, Trans. Linn. Soc. London, ser. 2, Zool., vol. 6, pt. 1, p. 54, pl. 3, figs. 39-46; pl. 4, figs. 1-4 1894. | Two females were obtained in the vertical haul from a depth of 1ooo meters at station 64, and these constitute the DISCUSSION OF SPECIES only record for the entire cruise. All the specimens thus far obtained have been deep-water captures and probably this copepod does not get into the upper 100 meters during the daytime. The species is distinguished by a very large sense organ at the tip of the second maxilla and by the structure of the fifth legs. Genus AMALLOTHRIX G. O. Sars, 1925 DEPTH IN METERS Daytime vertical distribution of certain species of Amallothrix: (1) arcuata, (2) obtustfrons, (3) propinqua. CHART 2. Amallothrix arcuata (G. O. Sars) (Figures 5, 131) [Scolecithricella arcuata G. O. Sars, Bull. Inst. océanogr. Monaco, no. 377, p. 10, 1920.] Three females of this species were taken from the 100- meter tow at station 35 off the Pacific end of the Panama Canal, and this was the only record for the cruise. It may be recognized by the strong curve of the frontal margin in lateral view and by the structure of the fifth legs. The species was reported by Sars (1925, p. 185) from the North Atlantic off the west coast of Scotland. This is the first record from the Pacific Ocean. Amallothrix obtusifrons (G. O. Sars) (Figure 128) [Amallophora obtusifrons G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 11, 1905.] Not found in the Atlantic plankton, but present at four stations in the eastern Pacific and one in the central region. It was taken in 3 50-meter tows and 2 100-meter tows, but did not appear at the surface either by day or by night. It is probably negative to light, but gave no evidence of nocturnal migration. All the S:boga specimens were taken in vertical hauls from depths of 1000 to 1500 meters and none at the surface." Amallothrix propinqua (G. O. Sars) (Figure 123) [Scolecithricella propinqua G. O. Sars, Bull. Inst. océanogr. Monaco, no. 377, p- 9, 1920.] Not present in the Atlantic plankton, but present at one station in the eastern and four in the central tropical Pacific near the Samoan Islands. It was taken in 1 daytime surface tow, I 50-meter tow, and 3 1oo-meter tows. The total num- ber of specimens was very small, and only one of them was 1 There is some question whether the data here given apply to this species or to Scolecithricella obtusifrons, which does not appear in this report. Since the author is deceased, it is not now possible to clear up the matter.—Eb. 171 found at the surface. The species was reported by Sars (1925, p. 178) from the temperate Atlantic, but these are the first records from the Pacific. Amallothrix valida (Farran) (Figures 7, 129) [Scolecithrix valida Farran, Fisheries, Ireland, Sci. Invest. for 1906, pt. 2, p. 55, pl. 5, figs. 14-17; pl. 6, fig. 7, 1908.] Two females were taken in the vertical tow from a depth of 1000 meters at station 64 in the southeastern region of the Pacific, and this is the only record for the cruise. Farran (19086, p. 55) originally obtained the species from deep water off the west coast of Ireland, and it was present in two vertical tows of the Szboga plankton, one from rooo and the other from 2000 meters. It would seem, therefore, that this is a deep-water species which usually keeps below the 100- meter level in the daytime. Genus ANOMALOCERA Templeton, 1837 Anomalocera patersonii Templeton (Figure 8) [Anomalocera patersonit Templeton, Trans. Entomol. Soc. London, vol. 2, pt. 1, p. 35, pl. 5, 1837.] This large and brilliantly colored species was found at two stations (9, 10) in the North Atlantic south of Greenland, and at two (113, 158) in the Pacific, the first off the coast of Japan and the second about rooo miles northeast of the Samoan Islands. Except for a single specimen listed for the 100-meter tow only at station 113, all the Carnegie records for the species were made with surface nets. This individual may have slipped into the net at a higher level as it was being lifted. Since this species has never been reported except at the surface, it can be regarded as strongly positive to light. Like Calanus finmarchicus, it has sometimes been found in great shoals at or close to the surface, but no trace of any- thing of that sort occurred in the Carnegie plankton. Genus ARIETELLUS Giesbrecht, 1892 Arietellus setosus Giesbrecht (Figures 3, 4) [Arietellus setosus Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, p. 415, pl. 29, figs. 1, 3-7, 9-13, 21; pl. 39, figs. 34-36, 1892.] A few specimens, including both sexes, were found in the 100-meter tow at station 42, and this was the only record for the cruise. The species has been reported by Esterly (1911, Pp. 335) from the San Diego region, California, and he men- tioned the rose color of the numerous setae from which the specific name is derived. This color was still very prominent in the Carnegie specimens after four years of preservation. Genus AUGAPTILUS Giesbrecht, 1889 Augaptilus longicaudatus (Claus) [Hemicalanus longicaudatus Claus, Die freilebenden Cope- poden, p. 129, pl. 29, 1863.] 172 A single female was found at each of three stations in the eastern Pacific and nowhere else. Six specimens of this species were obtained in the S:boga plankton by vertical hauls from 750 to 1500 meters. This is probably another deep-water species which usually stays below the 100-meter level in the daytime. The caudal rami in this species are much longer than any of the abdominal segments. Genus BATHYCALANUS G. O. Sars, 1905 Bathycalanus rigidus G. O. Sars [Bathycalanus rigidus G. O. Sars, Bull. Inst. océanogr. Monaco, no. 377, p. 2, 1920.] Six specimens of this species were found in the two deeper tows at station 118, and this is the only record for the cruise. According to Sars (1925, p. 19), this is a bathypelagic species and is found at considerable depths. It would seem as if it must come to the surface during the night, for otherwise these specimens would not have been found as far up as the 50-meter tow in the early forenoon. Genus CALANOPIA Dana, 1853 Calanopia americana F. Dahl (Figure 2) [Calanopia americana F. Dahl, Ber. Naturforsch. Gesellsch. Freiburg, n. s., vol. 8, p. 21, pl. 1, figs. 23-26, 18942. | Found in small numbers at three stations in the Caribbean region, at two of the stations in the 50-meter tow and at the third station in the roo-meter tow. In these few instances, therefore, the species was negative to light, but they do not furnish sufficient data for any general conclusion. The speci- mens reported in the Szboga plankton came from Bermuda and, together with those here recorded, will establish the form as pelagic rather than littoral. Calanopia elliptica (Dana) (Figure 10) [Pontella elliptica Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 27, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1132, 1853; pl. 79, fig. 6a, b, 1855.] A few females were taken at station 32 in the Caribbean, and both sexes were found abundantly near the Samoan Islands in the Pacific. The species was far more abundant in the S:boga plankton, where it was found in 32 surface tows, to of them taken during the night. Since it was captured at the surface here also, we may infer that it is usually positive to light. Genus CALANUS Leach, 1819 This is one of the oldest and best-known copepod genera, and its species are widely distributed in every ocean and in all zones. One of its species attains the largest number of individuals among the copepods and is known to congregate in countless swarms to the exclusion of all other species. Seyen species were present in the Carnegie plankton, three in the northern regions and the other four in the temperate and tropical regions. COPEPODS OF LAST CRUISE OF CARNEGIE is) /00 DEPTH IN METERS & Ss Cuart 3. Daytime vertical distribution of species of Calanus: (1) cristatus, (2) finmarchicus, (3) helgolandicus, (4) hyper- boreus, (5) minor, (6) propinquus, (7) tonsus. One species, cristatus, was confined to the two lower tows; the other six ap- peared at all three depths, but were more abundant in the deeper tows than at the surface. This was true even of finmarchicus, which was the only species that was least abundant at 50 meters, Calanus cristatus Krgyer [Calanus cristatus Krgéyer, Voy. comm. sci. Nord. Scandinavie . la corvette “La Recherche,” atlas, pl. 41, 1842-45; Natur- hist. Tidsskr., Kjobenhavyn, ser. 2, vol. 2, pp. 547, 553, 607, 1848-1849.] Found only at the Pacific stations north of latitude 40°, and hence, a boreal species. It was entirely confined to the two deeper tows, which indicates that it is negative to light, and its numbers were small except in the 100-meter tow at station 120. The specimens obtained had every appearance of being immature, since none could be found in which the rami of the fifth legs had more than two segments. The species has been recorded by Van Breemen (1907, p. 10) for the North Atlantic in the region traversed by the Carnegie, but did not appear in any of the tows taken in the Atlantic during the present cruise. Calanus finmarchicus (Gunner) [Monoculus finmarchicus Gunner, Skr. Kjobenhavnske Selsk., vol. 10, p. 175, figs. 20-23, 1765.| Like the preceding species, this well known copepod is a boreal form and except at station 130 was found only above latitude 40° in both oceans. It was present in 11 surface tows, 10 50-meter tows, and 13 100-meter tows. The fact that no trace was found of the countless swarms of this species re- ported from the North Atlantic may be due to the season of the year when the Carnegie tows were taken. It is possible that similar swarms might exist in Bering Sea north of the Aleutian Islands at the right time of year. The Carnegie records seem to substantiate Russell’s (1928) statement that this species is negative to light at medium temperatures, but becomes positive at lower temperatures. Calanus helgolandicus (Claus) [Cetochilus helgolandicus Claus, Die freilebenden Copepoden, p. 171, pl. 26, figs. 2-9, 1863.] This species was abundant over the entire Atlantic north of the equator but was found at only four stations in the Pacific. It was captured in 4 nocturnal and 16 diurnal surface tows, 18 50-meter tows, and 23 1oo-meter tows. It is also often found in about equal abundance at all three depths at DISCUSSION OF SPECIES a station, and when it is restricted to a single depth this may be any one of the three indiscriminately. Accordingly it must be designated as fairly indifferent to light, but may become negative to the stronger light of the tropics. Calanus hyperboreus Kr¢yer [Calanus hyperboreus Kréyer, Kong. Danske Vidensk. Selsk., Naturvidensk. og. math. Afh., vol. 7, p. 310, pl. 4, 1838.] As the specific name indicates, this is a boreal species and is confined to northern latitudes. It was not present in the Carnegie plankton from the North Atlantic, but has been re- ported from that region by Giesbrecht (1892, p. 91) and Sars (1925, p. 6). It was taken in the Pacific in 4 surface tows, 11 50-meter tows, and 10 100-meter tows, and development stages were abundant in 3 of the surface tows. Besides being larger than those of the preceding species, both the early stages and the adults were much darker and more opaque. Calanus minor (Claus) [Cetochilus minor Claus, Die freilebenden Copepoden, p. 172, 1863.] Very widely distributed in both oceans, but with numerous gaps within which it was entirely absent from the plankton. It was present in 11 nocturnal and 32 diurnal surface tows, 73 50-meter tows, and 66 100-meter tows. Although it thus shows considerable preference for the two deeper tows, it was nevertheless often equally divided among the three depths. In many of the specimens taken in the tropics the setae of the caudal rami were more densely plumose than usual and tinged with red. Calanus propinquus Brady [Calanus propinquus Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 34, pl. 2, figs. 1-7; pl. 14, figs. 10, 11, 1883.] In the Atlantic this species was almost entirely confined to the Caribbean region, but it was present in every region of the Pacific. Its distribution in the latter ocean, however, was very irregular, with numerous and extensive gaps. It was found in 7 nocturnal and 6 diurnal surface tows, 18 50-meter tows, and 23 roo-meter tows. It thus showed a preference for the deeper tows in the daytime but came to the surface at night. The larger size and the pointed posterior corners of the fifth thoracic segment will distinguish the species. Calanus tonsus Brady [Calanus tonsus Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 34, pl. 4, figs. 8-9, 1883.] This species was not found in the Atlantic plankton, al- though it has been reported from that ocean both north and south of the equator. In the Pacific it was practically con- fined to the eastern part south of the equator, where it was captured in 2 nocturnal and 2 diurnal surface tows, 3 50- meter tows, and 4 100-meter tows. It was originally reported by Brady (1883, p. 34) as from this locality as well as else- where, and was found by Farran (1929, p. 216) in the Terra Nova plankton south of New Zealand. 173 Genus CALOCALANUS Giesbrecht, 1888 Calocalanus pavo (Dana) [Calanus pavo Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p- 13, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1061, 1853; pl. 72, fig. 12a, b, 1855-] This species was dispersed everywhere in both oceans except in the extreme northern parts, but usually in small numbers. The distribution, however, was very irregular, with numerous gaps and great variation in abundance. It was present in 5 nocturnal and 53 diurnal surface tows, 78 50- meter tows, and 65 roo-meter tows. It is thus more or less indifferent to light and is often equally distributed at all three depths, or any two of them, at the same time. The four enlarged and fanlike plumes on each caudal ramus combined with the profuse armature of the anterior antennae give exceptional beauty to the living copepod. These are always broken off in preserved material, and the specimens have a ragged and uncouth appearance. Calocalanus plumulosus (Claus) (Figure 18) [Calanus plumulosus Claus, Die freilebenden Copepoden, p. 174, pl. 26, figs. 15, 16, 1863.] Not present in the Atlantic plankton but fairly well dis- tributed in the Pacific, where it was taken in 10 nocturnal and 5 diurnal surface tows, 25 50-meter tows, and 25 100- meter tows. When alive this copepod carries an enormous plume on the left caudal ramus, but this is never seen on a preserved specimen. Furthermore, all the appendages are so brittle that they are usually broken and it is very rare to find a specimen with anything except the fifth legs intact. For- tunately these legs are quite characteristic and will serve to identify the species. Calocalanus styliremis Giesbrecht (Figures 12, 14) [Calocalanus styliremis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 333, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 176, 185, pl. 9, figs. 15, 18, 29; pl. 36, figs. 46-48, 1892. ] Found in the Sargasso and Caribbean regions and widely dispersed in the Pacific. The distribution in the latter ocean is such that the species is of rare occurrence although found 44 times from station 4o to station 15g. It was taken in 16 diurnal surface tows, 32 50-meter tows, and 23 100-meter tows. It is thus negative at least to strong light. Genus CANDACIA Dana, 1846 This is a temperate and tropical genus and was not found north of latitude 50° in the Atlantic or 40° in the Pacific. Several of the species have a world-wide distribution and most of them were more abundant in the deeper tows than at the surface. See chart 4, on following page. is) 100 DEPTH IN METERS a S 100 DEPTH IN METERS GH S Cuart 4. Daytime vertical distribution of species of Candacia: (1) aethiopica, (2) armata, (3) bipinnata, (4) bispinosa, (5) catula, (6) curta, (7) falcifera, (8) longimana, (9) norvegica, (10) pachydactyla, (11) simplex, (12) tenuimana, (13) trun- cata, (14) varicans. Three of the fourteen species were confined to the 100-meter tow and two others to the two deeper tows. Of the nine species present in all three tows, two were equally dis- tributed, two were more abundant in the 1oo-meter tow, and five were more abundant in the 50-meter tow. Candacia aethiopica (Dana) [Candacia ethiopica Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 23, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1115, 1853; pl. 78, fig. 5a-e, 1855.] Found in the temperate and tropical Atlantic and in the eastern and central tropical Pacific. It was present in 4 noc- turnal and 8 diurnal surface tows, 8 50-meter tows, and 7 roo-meter tows. These records indicate that it is more or less indifferent to ordinary light, but becomes negative to the strong light of the tropics, where it is found more often in the two deeper tows. The legs and the entire thorax behind the head are so dark a brown as to appear virtually black, and thus serve to distinguish the species. In the Siboga plankton this species was found more often at the surface than in the deep vertical tows. Candacia armata (Boeck) [Candace armata Boeck, Forhandl. Vidensk. Selsk. Christiania, vol. 14, p. 39, 1872.] Found once in the eastern Pacific and three times in the western part off the coast of Japan, being present in each of the three tows. Although it was not found in the Carnegie plankton from the Atlantic, it has been reported from the North Atlantic by Cleve (1900-1901, p. 141; 19008, p. 51; as Candace pectinata). Sars in his Crustacea of Norway (1902, p. 135) stated that all the specimens of this species which he procured from the coasts of Norway were near the surface of the sea, and this would make them positive to light. The species may be recognized by the peculiar asymmetry of the urosome in the female and the genital segment in the male. COPEPODS OF LAST CRUISE OF CARNEGIE Candacia bipinnata (Giesbrecht) [Candace bipinnata Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 815, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 424, 439, pl. 22, fig. 20; pl. 39, figs. 27, 29, 1892.] Found only in the Pacific at widely separated localities, once at the surface in a nocturnal tow, twice in the 50-meter tow in the daytime, and five times in the 100-meter tow. These few specimens thus show a definite negative photo- tropism, but are not numerous enough to warrant a general conclusion. This was reported by Farran (1929, p. 272) as the most plentiful species of the genus off the coast of New Zealand, and it has also been reported from the North and South Atlantic. Candacia bispinosa (Claus) (Figure 9) [Candace bispinosa Claus, Die freilebenden Copepoden, p. 191, pls. 27, 28, 1863.] Found in the temperate and tropical Atlantic and in the eastern and central Pacific south of the equator, also north of the equator in the western Pacific, reaching latitude 40°. It was present in 14 nocturnal and 1g diurnal surface tows, 45 50-meter tows, and 45 100-meter tows. These records indicate a preference for the two deeper tows, but also a frequent occurrence at the surface both by day and by night. Next to simplex this was the most widely distributed species of the genus, and the number of specimens reached into the hundreds, in sharp contrast with the 3 which constituted the total for the Szdoga plankton. Candacia catula (Giesbrecht) [Candace catula Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 815, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 425, 440, pl. 21, fig. 13; pl. 22, figs. 3, 27, 28, 1892.] A single female of this species was found in the roo-meter tow at station 155 in the central Pacific close to the equator. Again we find a sharp contrast with the Siboga plankton, in which this species was found to be well distributed over the Pacific. Many of the captures, however, were made in ver- tical hauls from considerable depths, hence it is possible that this species descends below the 1oo-meter level and remains there in the daytime, and thus escaped most of the Carnegie tows. Candacia curta (Dana) (Figure 19) [Candace curta Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 23, 1849; U. S, Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1116, 1853; pl. 78, fig. 6a-d, 1855.] Found in the eastern Pacific close to the equator and in the western Pacific north of the equator. It was taken in 2 surface tows, 5 50-meter tows, and 2 100-meter tows, with a total for all the tows of 21 specimens. The species has been reported from the California coast by Esterly (1905, p. 196) and from the tropical Atlantic by Cleve (1904, p. 186), but did not occur in the Carnegie plankton from the Atlantic. DISCUSSION OF SPECIES Candacia falcifera Farran (Figure 13) [Candacia falcifera Farran, British Antarctic (Terra Nova) Exped., pt. 10, Zool., vol. 8, no. 3, p. 270, fig. 28, 1929.] Two females were obtained from the 1oo-meter tow at station 23 in the tropical Atlantic, and this was the only record for the cruise. Although the species was established by Farran (1929, p. 270) on specimens obtained by the Terra Nova expedition in the Antarctic south of New Zealand, these 2 tropical Atlantic specimens show exactly the same characteristics, especially as regards the fifth legs (fig. 13). Candacia longimana (Claus) (Figure 26) [Candace longimana Claus, Die freilebenden Copepoden, p. 140, pl. 27, 1863.] Not found in the Atlantic plankton but widely and very irregularly dispersed in the eastern, central, and western Pacific within the tropics. It was taken in 2 surface tows, 3 50-meter tows, and 9 roo-meter tows, and in every instance the abundance record was 5 or less. The small, curved, and shriveled spine at the right posterior corner of the fifth thoracic segment is a good character for identifying the species. Candacia norvegica (Boeck) (Figure 6) [Candace norvegica Boeck, Forhandl. Vidensk, Selsk. Chris- tiania, p. 235, 1865.] Found near latitude 40° in the western part of the North Atlantic, in the Sargasso and Caribbean regions, and in the eastern, central, and western Pacific. It was present in 12 nocturnal and 4 diurnal surface tows, 22 50-meter tows, and I5 1o0o-meter tows. It thus preferred the two deeper tows during the daytime but migrated frequently to the surface at night. Candacia pachydactyla (Dana) (Figure 15) [Candace pachydactyla Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 23, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1113, 1853; pl. 78, figs. 2a, b, 3a, b, 4a-c, 1855.| Found in the central and Caribbean regions of the Atlantic and chiefly in the eastern part of the Pacific. It was taken in 2 nocturnal and 3 diurnal surface tows, 9 50-meter tows, and 7 100-meter tows, but the number of specimens was too small for any general statement. A. Scott (1909, p. 153) listed it as moderately common in the Siboga plankton and stated that it was widely distributed in tropical seas. The Carnegie records would probably have been more numerous had the tows been taken below 100 meters. Candacia simplex (Giesbrecht) (Figures 16, 17) [Candace simplex Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. I, p. 815, 1889; Fauna und Flora des Golfes 175 von Neapel, vol. 19, pp. 424, 440, pl. 21, figs. 10, 21, 25, 30, 31; pl. 22, figs. 21, 29; pl. 39, figs. 3, 14, 1892.] This was the most widely distributed of all the Candacia species in both oceans, especially in the Pacific, where it was found in every region except the extreme north. It was taken in 16 nocturnal and 32 diurnal surface tows, 73 50-meter tows, and 58 r1oo-meter tows. In the daytime, therefore, it was more often present in the deeper tows, especially at 50 meters. But it was frequently equally distributed in all three tows at the same time, and was seldom restricted to a single depth. Wherever it remains during the day, it evidently migrates regularly to the surface at night, since it appeared in so many of the nocturnal tows. Candacia tenuimana (Giesbrecht) [Candace tenuimana Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 814, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 424, 439, pl. 21, figs. 8, 28, 29; pl. 22, figs. 2, 30, 37, 1892.] A single female was captured in the 1oo-meter tow at station 115 off the Japan coast in the Pacific, and this was the only record. The S:boga plankton yielded 2 specimens in a vertical haul from a depth of 1500 meters. This suggests not only that the species is rare, but also that it is more likely to be found in the depths below the 1o0-meter level. It has been reported from the South Atlantic by Cleve (1904, p. 187) and from the western Mediterranean and the tropical Pacific by Giesbrecht (1808, p. 128). Candacia truncata (Dana) (Figure 11) [Candace truncata Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 24, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1118, 1853; pl. 78, fig. 8a-d, 1855.] This species was not found in the Atlantic plankton, but was well distributed in the eastern and western Pacific and lacking in the northern part. It was found in 3 nocturnal and 1 diurnal surface tows, 24 50-meter tows, and 25 roo-meter tows. In the daytime, therefore, it was practically confined to the two deeper levels, but at night it migrated occasionally to the surface. In the S/boga plankton it was found in 33 of the surface tows, 10 of which were nocturnal, and in 7 vertical tows from considerable depths. Candacia varicans (Giesbrecht) [Candace varicans Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 424, 439, pl. 21, figs. 3, 4, 11, 24; pl. 22, figs. 10, 25; pl. 39, figs. 2, 23, 1892.] Found in the tropical region of the Atlantic and in the western Pacific; entirely confined to the two deeper levels, appearing in 5 50-meter tows and g 1o0-meter tows. It was obtained originally by Giesbrecht (1892, p. 424) from the Mediterranean, but has been reported from the North Atlantic and the South Pacific, off the New Zealand coast. The structure of the fifth legs, especially those of the male, furnishes a ready means of identifying the species. 176 Genus CANTHOCALANUS A. Scott, 1909 Canthocalanus pauper (Giesbrecht) [Calanus pauper Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 331, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 91, 129, pl. 6, fig. 4; pl. 8, fig. 25, 1892.] Not present in the Atlantic plankton but well scattered over the Pacific, with, however, five large gaps in its distribu- tion, one each in the northern, eastern, southern, central, and western regions. It was taken in 5 nocturnal and 20 diurnal surface tows, 33 50-meter tows, and 30 1oo-meter tows. These records indicate more or less indifference to light, and this conclusion is supported by the fact that the species was found equally distributed in all three tows at the same time, or in two of them. On the other hand, it was found more often in the two deeper tows during the day, and probably becomes negative as the intensity of the light increases. It is worthy of note that this species was captured only in surface tows during the Szboga expedition and not in any of the ver- tical tows from different depths. Genus CARNEGIELLA, new genus Body of typical cyclops form, metasome five times as wide as urosome, considerably swollen dorsally and ventrally. First antennae slender, six-segmented, the terminal segment linear and four times as long as the rest of the antenna. Second antenna uniramose and five-segmented; maxillipeds chelate; rami of first four pairs of legs three-segmented; fifth legs lacking in the female; male unknown. Genotype. Carnegiella gracilis (Cyclopoida). Carnegiella gracilis, new species (Figures 20-25) Occurrence. A single female was found in the 100-meter tow at station 151 north of Samoa in the central Pacific. Description of female. Metasome pyriform, a little more than twice as long as wide, widest at the center and strongly narrowed anteriorly and posteriorly. Head fused with the first thoracic segment and much longer than the free thorax. Urosome six-segmented, much narrower than fourth segment of metasome, about same width throughout. Genital segment longer but scarcely wider than any of the abdominal seg- ments; the latter all of about the same length and width except the anal segment, which is widened posteriorly. Caudal rami longer than the anal segment and pointed pos- teriorly, where each is armed with three setae, one on the outer and two on the inner margin. Between the setae the lamina of the ramus projects backward and ends in two processes, the outer one longer than the inner and tipped with a hair. The first antennae are six-jointed, the five basal joints moderately swollen and tapering distally. The terminal seg- ment is linear and four times as long as the other five seg- ments combined. The fourth segment carries an aesthetask which is linear and closely appressed to the terminal seg- ment, and reaches slightly beyond the tip of the latter. The , COPEPODS OF LAST CRUISE OF CARNEGIE | ‘ ) second, third, and fourth segments are setose, but the long terminal segment is naked except for a tuft of setae at its ~ very tip. ! The second antennae are uniramose, slender, and five- segmented, the third segment the longest and the fourth — segment the shortest. The basal segment carries a small seta — on its inner margin, the fourth segment has a similar one on its outer margin at the distal corner, and the terminal segment is tipped with a single larger seta. The mandibles — and maxillae were not removed for examination, as this would have destroyed the solitary specimen. The maxillipeds are two-segmented, rather stout, with a chela at the tip of the second segment. The first four pairs of legs are biramose and each ramus is three-segmented; the armature of these legs is very peculiar, as can be seen from figures 24 and 25. In the first and second legs the spines on the outer margins of the exopods are arranged 1, 1, 2 and are normally developed. In the third and fourth legs the spine on the basal segment is reduced to a tiny rudiment, the one on the middle segment is somewhat better developed, and there is but one on the end segment at the distal corner. The first endopod carries on the outer margin of each of its three segments a single seta; on the inner margins there are one, two, and three setae respectively, and two more at the tip of the third segment, eleven in all, which is an exceptionally large number for a first endopod. The third and fourth endopods have no setae on the outer margin, and on the inner margin there are one, two, and two respectively on the three segments, with a single seta at the end of the third segment, six in all. Total length, 1.25 mm; length of metasome, 0.85 mm; length of urosome, 0.45 mm. Type. U.S. Nat. Mus. no. 64002. Remarks. This species is distinguished by the exceptional length and linearity of the last segment of the first antennae, by the structure of the maxillipeds and the caudal rami, and by the armature of the swimming legs. Genus CENTRAUGAPTILUS G. O. Sars, 1920 Centraugaptilus rattrayi (T. Scott) [ Augaptilus vattrayi T. Scott, Trans. Linn. Soc. London, ser. 2, Zool., vol. 6, pt. 1, p. 36, pl. 2, figs. 25-37, 1894.] A few badly preserved specimens of this species were ob- tained in the roo-meter tow at station 23 in the tropical Atlantic. It was first described by T. Scott (1894, p. 36) as from the Gulf of Guinea, but was afterward reported from various localities in the North Atlantic by Farran (19088, p- 78) and Sars (1925, p. 304). ¥ Genus CENTROPAGES Kréyer, 1849 This genus was well distributed in both oceans except in- the northern parts and the southern part of the Pacific, and _ was more abundant in the tropics. Although most of the species are pelagic in habitat, some of them come close to shore and even enter the mouths of rivers and harbors. See chart 5, on following page. DISCUSSION OF SPECIES DEPTH IN METERS Cuart 5. Daytime vertical distribution of species of Centro- pages: (1) calaninus, (2) chierchiae, (3) elongatus, (4) furcatus, (5) hamatus, (6) typicus, (7) violaceus. Two of the species were confined to the surface tow, and one appeared both at the surface and in the roo-meter tow, but not in the 50-meter tow. Four were present at each of the three depths, one of these being least abundant in the roo-meter tow and the remaining three least abundant at the surface. Centropages calaninus (Dana) (Figure 30) [Cyclopsina calanina Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 25, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, pp. 1105, 1106, 1853; pl. 78, fig. 10a, b, 1855.] Not found in the Atlantic plankton, but dispersed over the entire Pacific with two extensive gaps in distribution, one in the southeastern part, the other in the extreme north. It was present in 13 nocturnal and 34 diurnal surface tows, 41 50- meter tows, and 25 100-meter tows, and in the vertical tow from 1000 meters, station 64. It was sometimes present equally in each of the three tows at the same time, but was found more often in the two upper tows. More than half the abundance records are expressed in numerals, indicating a paucity in the number of individuals. Centropages chierchiae Giesbrecht [Centropages chierchiae Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 811, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 304, 320, pl. 17, figs. 38, 39, 45; pl. 18, fig. 5; pl. 38, figs. 3, 7, 1892.] Three specimens of this species, including both sexes, were obtained in the surface tow at station 2 near the Sargasso region, and this was the only record for the cruise. This species was originally obtained by Giesbrecht (1892, p. 304) from the Strait of Gibraltar, and has since been reported from the North Atlantic by Cleve (1904, p. 187) and from the Indian Ocean by Thompson and Scott (1903, p. 246). Centropages elongatus Giesbrecht [Centropages elongatus Giesbrecht, Zool. Jahrb., Abth. Syst., vol. 9, p. 322, pl. 5, figs. 3-6, 1896.] Not present in the Atlantic plankton, but found once in the southeastern Pacific, once in the extreme western part, and at most of the stations between the Hawaiian Islands and Samoa. It was taken in 1 nocturnal and 4 diurnal surface tows, II 50-meter tows, and 11 1oo-meter tows. It was thus largely confined to the two deeper tows, but gave evidence of migration to the surface at night. The appendages of this copepod seem exceptionally brittle; nearly every specimen was TTT. badly mutilated, though the other copepods in the same tow were well preserved. Centropages furcatus (Dana) [Catopia furcata Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 25, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1173, 1853; pl. 74, fig. 1a-d, 1855.] Well distributed in the Atlantic except at the extreme north, and in the Pacific confined to the eastern and central parts. It was present in 7 nocturnal and 16 diurnal surface tows, Ig 50-meter tows, and 21 100-meter tows. It was thus quite evenly divided among the three depths and often ap- peared in them all at the same time. The long caudal rami and the small accessory spines inside the larger ones at the posterior corners of the fifth thoracic segment easily identify the species. Centropages hamatus (Lilljeborg) [Ichthyophorba hamata Lilljeborg, De crustaceis ex ordinibus tribus: Cladocera, Ostracoda et Copepoda, in Scania occur- rentibus, p. 185, pls. 21, 26, 1853.] Found at six localities in the Atlantic and at only two in the Pacific, in 4 nocturnal and 4 diurnal surface tows and 2 roo-meter tows, but nowhere in a 50-meter tow. Sars in his Crustacea of Norway (1902, p. 76) said of this species, “It is a true pelagic form, occurring as a rule close to the surface of the sea.” And yet he found it common in the fjords and along the whole coast of Norway, and it is one of the species that frequently comes into harbors and estuaries. It is widely dis- tributed in the North Atlantic and occurs in sufficient abun- dance to form an essential factor in the food of certain pelagic fishes. Centropages typicus Krgyer [Centropages typicus Krgyer, Naturhist. Tidsskr., Kj6benhavn, ser. 2, vol. 2, p. 588, pl. 6, 1849.] Found only in the surface tow at station 6 in the Atlantic southwest of England, and not at all in the Pacific. Sars in his Crustacea of Norway (1902, p. 75) said of this species, “We are justified in regarding it as a true Atlantic form. Off the Norwegian coast it occurs both in the open sea and in the fjords, being often found in considerable abundance at the very surface of the sea.” About the same may be said of it along the eastern coast of North America, where it seems to be more of a littoral than a pelagic form, entering most of the harbors and estuaries, and showing a decided preference for the surface. Centropages violaceus (Claus) [Ichthyophorba violacea Claus, Die freilebenden Copepoden, p. 199, pl. 35, figs. 13, 14, 1863.] Found in and near the Sargasso region and in the central Pacific about rooo miles east and southeast of the Hawatian Islands. It was present in 1 nocturnal and 3 diurnal surface tows, 9 50-meter tows, and 6 1oo-meter tows. It appeared thus chiefly in the two deeper tows, but its presence in the nocturnal tow shows that it migrates to the surface at night. It was not found in either the Challenger or the Siboga plankton, the specimens named violaceus by Brady (1883, 178 p. 83) being a different species, but it has been reported by Farran (1929, p. 255) from the Atlantic and the South Pacific. The lateral margins of the metasome are often in- dented at every joint, giving the body a peculiar nodal ap- pearance. Genus CHIRIDIELLA G. O. Sars, 1907 Chiridiella species Only one of the three species accredited to this genus, all of which occur in the Atlantic, has ever been reported .from the Pacific. The three tiny representatives of this genus taken in the vertical tow from 1000 meters at station 64 are too immature to admit identification with the species C. macro- dactyla Sars, which does occur in the Pacific. From the man- ner in which the haul was made, it is impossible to say at which level the specimen was captured between 1000 meters and the surface. Genus CHIRIDIUS Giesbrecht, 1892 Chiridius poppei Giesbrecht [Chiridius poppe: Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, p. 224, pl. 14, figs. 14-18, 1892.] A single female, not fully developed but apparently belong- ing to this species, was taken in the vertical haul from a depth of 1000 meters at station 64 in the southeastern Pacific, also 2 specimens (juvenile males) were found in 50-meter tows off the coast of Japan. It is worthy of note that 5 of the 6 specimens obtained in the S/boga plankton were taken in vertical hauls from depths of 700 to 1500 meters. This indi- cates that the species is a deep-water form and not likely to be found in the upper 100 meters except at night. It was re- ported in a surface haul off New Zealand by Farran (19209, p. 255), but the time at which the tow was taken was not given. Genus CLAUSOCALANUS Giesbrecht, 1888 Clausocalanus arcuicornis (Dana) [Calanus arcuicornis Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 12, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1056, 1853; pl. 72, fig. 7a, b, 1855.) Found in all the Atlantic plankton except at the far north, and at practically every locality in the Pacific, often very abundant. It was taken in 29 nocturnal and 76 diurnal sur- face tows, 93 50-meter tows, and g2 roo-meter tows, and in the vertical tow from 1000 meters at station 64. It was also frequently found at all three depths in equal abundance, and was very seldom restricted to a single depth. Such a vertical distribution indicates indifference to light under normal con- ditions, and its horizontal or geographical distribution indi- cates that it is equally indifferent to temperature, except in extremes. It evidently stays at the surface during the night, but is found somewhat more often in the two deeper tows during the day. COPEPODS OF LAST CRUISE OF CARNEGIE Clausocalanus furcatus (Brady) (Figures 27-29) [Drepanopus furcatus Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 77, pls. 4, 24, 1883.] Not found in the Atlantic plankton, but abundant in the eastern, southern, and central parts of the Pacific, though not in the western and northern parts. It was present in 22 noc- turnal and 28 diurnal surface tows, 30 50-meter tows, and 40 r00-meter tows. Like the preceding species, it was often taken equally at all three depths at the same time. In the Siboga plankton it was found in 24 surface tows, 10 of them at night, and 10 vertical hauls from considerable depths. In the tropics, where the light was strongest, it was often con- fined to the deeper tows. Genus CLYTEMNESTRA Dana, 1847 Clytemnestra rostrata (Brady) [Goniopsyllus rostratus Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 107, pl. 42, figs. 9-16, 1883.] Found only at station 8 southeast of Iceland in the Atlantic, but scattered irregularly over the entire Pacific and common in the central region. It was taken in 5 nocturnal surface tows, 16 50-meter tows, and 28 roo-meter tows. Its absence from the diurnal surface tows shows that it is negative to light, and its presence in the nocturnal surface tows shows that it mi- grates to the surface at night. It is worthy of note that the 5 specimens from the S/boga plankton were all captured at or near the surface. Clytemnestra scutellata Dana [Clytemnestra scutellata Dana, Proc. Amer. Acad. Arts and Sci., vol. 1, p. 153, 1847; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p, 1194, 1853; pl. 83, fig. 12a-f, 1855.] This species was found at ten of the Atlantic localities and its Pacific distribution was similar to that of the preceding species, but it was somewhat more abundant. It was present in 4 nocturnal and 2 diurnal surface tows, 35 50-meter tows, and 39 100-meter tows. In view of its comparative abundance in the Carnegie plankton, it seems strange that this species did not appear at all in either the Challenger or the Siboga plankton. Like rostrata, it is negative to light and prefers the two deeper tows during the daytime, but migrates to the sur- face at night. Genus CONAEA Giesbrecht, 1891 Conaea gracilis (Dana) [Antaria gracilis Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1229, 1853; pl. 86, fig. t1a-d, 1855.] A few specimens were found in the two deeper tows at station 35 off the Pacific end of the Panama Canal, and this was the only record for the cruise. It is worthy of comment that all the 15 specimens of this species in the Szboga plank- ton were captured in vertical hauls from depths of 700 to DISCUSSION OF SPECIES 2000 meters. This strongly suggests that the copepod is a deep-water form which could be expected only rarely in the upper 100 meters. Genus COPILIA Dana, 1849 This genus is widely distributed in tropical and temperate oceans, chiefly the former. All its species showed a preference for the deeper levels, but denticulata was often, and quadrata rarely, found at the surface. The species were also more or less gregarious, occurring together at consecutive stations in some localities, and entirely absent from the plankton in others, often for long distances. Copilia denticulata Claus [Copilia denticulata Claus, Die freilebenden Copepoden, p. 161, pl. 25, 1863.] Found at eight Atlantic localities, and irregularly scattered over the entire Pacific with large gaps in the southeastern and northern parts. It was present in 3 nocturnal and 24 diurnal surface tows, 48 50-meter tows, and 31 1o0-meter tows. It was thus found most frequently at the deeper levels in the day- time, especially at the 50-meter level, but migrated to the surface sometimes at night. Copilia mirabilis Dana [Copilia mirabilis Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 40, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1232, 1853; pl. 86, fig. 14a, b, 1855.| Not present in the Atlantic plankton, but found at five stations in the Pacific, one in the southeastern part and four in the western part. At two of the stations the species was in the 50-meter tow, at two others in the roo-meter tow, and only once at the surface. In the Szboga plankton this species was captured in 47 surface tows, 10 of which were nocturnal, and in 8 vertical tows from considerable depths. As no simul- taneous tows at different depths were taken on the Szboga expedition, the most that can be said is that this copepod has been taken so often at the surface in the daytime that it must be at least indifferent if not positive to light. Copilia quadrata Dana [Copilia quadrata Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 40, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1233, 1853; pl. 86, fig. 15a-d, 1855.] Not present in the Atlantic plankton, but well scattered over the Pacific, with large gaps in distribution in the south- eastern and northern parts. It was taken in 1 nocturnal and 4 diurnal surface tows, 5 50-meter tows, and 33 100-meter tows. Accordingly it was almost entirely confined to the two deeper tows, especially the 1oo-meter tow, in the daytime, and must be negative to light. During the S:boga expedition it was taken in 21 surface tows, 6 of which were nocturnal. 179 Copilia recta Giesbrecht [Copia recta Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 480, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 648, 658, pl. 50, fig. 4, 1892.] This species was confined to four stations in the western Pacific between the Mariana Islands and Japan, and was present only in the two deeper tows, not appearing at the surface. As far as is known, this copepod has been reported only from the tropical Pacific and does not appear in any of the lists of the larger plankton expeditions. Copilia vitrea (Haeckel) [Hyalophyllum vitreum Haeckel, Ztschr. f. Med. u. Naturwiss., Jena, vol. 1, p. 63, pl. 1, 1864.| Not present in the Atlantic plankton, but irregularly scat- tered at many stations long distances apart in the Pacific. It was found in 8 50-meter tows and 7 100-meter tows, but did not appear at the surface. Although not found in the Atlantic during the present cruise, it has been reported from the tropical Atlantic by Giesbrecht (1892, p. 647). Genus CORYCAEUS Dana, 1845 The genus Corycaeus is confined to the temperate and tropical regions and is rarely found above latitude 40° north or below 40° south. It belongs, furthermore, to the epiplank- ton, and the species are all found within the upper 100 meters. In spite of this, the vertical distribution of the various species shows considerable diversity; see chart 6, on page 180, The names of the species are those given in the admirable monograph on the Corycaeidae by Maria Dahl (r1gr2), but it has not been deemed necessary to include the subgenera. Corycaeus agilis Dana [Corycaeus agilis Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 37, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, pp. 1217, 1218, 1853; pl. 85, fig. toa, b, 1855.| Found at six localities in the Sargasso and Caribbean re- gions, and irregularly scattered over the entire Pacific except the north, but more abundant in the southeastern part. It was taken in 44 surface tows, 17 50-meter tows, and 11 roo-meter tows, and is thus a surface species, having a larger surface predominance than any of the other species. Corycaeus andrewsi Farran (Figure 36) [Corycaeus andrewsi Farran, Proc. Zool. Soc. London, 1911, p. 294, pl. 13, figs. 7-9; pl. 14, figs. 1-4, 1911.] This species was not present in the Atlantic plankton, and in the Pacific was found chiefly in the southeastern part. It was taken in 1 nocturnal and 5 diurnal surface tows, 3 50- meter tows, and 6 100-meter tows. Farran’s (1911, p. 294) original specimens were obtained in shallow water near the shore of Christmas Island in the Indian Ocean, but other specimens of both sexes were subsequently found by Maria Dahl (1912, p. 78) in the western tropical Pacific. 180 100 DEPTH IN METERS H S 100 DEPTH IN METERS S.) is} /00 DEPTH IN METERS a Ss Cuart 6. Daytime vertical distribution of species of Corycaeus: (1) agilis, (2) andrewst, (3) anglicus, (4) catus, (5) claust, (6) crassiusculus, (7) dubius, (8) flaccus, (9) furcifer, (10) gies- brechti, (11) lautus, (12) limbatus, (13) longistylis, (14) lub- bockii, (15) minimus, (16) ovalis, (17) pacificus, (18) pumilus, (19) robustus, (20) speciosus, (21) typicus. Each species was found somewhere at each of the three depths. Seven were least abundant in the roo-meter tow, more abundant in the 50-meter tow, and most abundant at the surface. Five were just the re- verse, least abundant at the surface and most abundant in the 1oo-meter tow. Six were most abundant in the 50-meter tow and less abundant in the other two tows; two were least abundant in the 50-meter tow, and one was equally abundant in all three tows. Corycaeus anglicus Lubbock (Figure 43) [Corycaeus anglicus Lubbock, Ann. and Mag. Nat. Hist., ser. 2, vol. 20, p. 408, pl. 11, figs. 14-17, 1857.] Found at five localities in the western and Caribbean re- gions of the Atlantic and at ten stations in the Pacific, chiefly in the central part. It was present in 9 surface tows, 4 50- meter tows, and 3 100-meter tows. It has been taken hitherto chiefly in the northern Atlantic, and has been pronounced by Sars in his Crustacea of Norway (1918, p. 196) “a pro- nouncedly pelagic animal, which has its true home in the open sea and only quite accidentally is thrown by the currents nearer to the shores.” From these Carnegie records it would seem to prefer the surface rather than the greater depths, and this agrees with the statements of other observers. Corycaeus catus F. Dahl [Corycaeus catus F. Dahl, Verhandl. Deut. zool. Gesellsch., vol. 4, Miinchen, p. 72, 18940.] COPEPODS OF LAST CRUISE OF CARNEGIE This species was not present in the Atlantic plankton, but was widely scattered over the Pacific, with large gaps in the distribution. It was taken 19 times in the roo-meter tow, 17 times in the 50-meter tow, and 14 times at the surface in the daytime and 9g times at night. It thus shows a slight prefer- ence for the greater depths during the day, but migrates rather regularly to the surface at night. Only the females of the species were known at first, and its validity was in doubt, but the descriptions and figures of both sexes by Maria Dahl (1912, p. 99) fully established it. Corycaeus clausi F. Dahl (Figure 42) [Corycaeus clausi F. Dahl, Verhandl. Deut. zool. Gesellsch., vol. 4, Munchen, p. 73, 18940.] This species was present twice in the Atlantic plankton, one of the localities being a nocturnal surface tow; it was also taken in 3 nocturnal surface tows in the Pacific. In the day- time it was found in 8 surface tows, 4 50-meter tows, and 2 r00-meter tows. It is evidently not abundant anywhere, and in these few Carnegie records showed a preference for the surface rather than for the deeper tows. From the records of other investigators it would seem to be more of an Atlantic than a Pacific form. Corycaeus crassiusculus Dana [Corycaeus crassiusculus Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 36, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, p. 1214, 1853; pl. 85, fig. 7, 1855.] This is the most widely distributed and most abundant species of the genus, and was found everywhere in both oceans except in the far north and in the four southernmost stations of the Pacific. It was taken in 16 nocturnal and 84 diurnal surface tows, 103 50-meter tows, and 77 100-meter tows, and was frequently found in all three tows at the same station. These records indicate more or less indifference to light, with a moderate preference for the 50-meter tow. Dana (1849, pp. 36, 38; 1853, pp. 1214, 1222) originally described a male, crassiusculus, and a female, venustus, in the same paper, and these have since been identified as the two sexes of the same species. Hence the name of the male, described first, must be taken for both sexes, and the name of the female dropped. Corycaeus dubius Farran (Figure 40) [Corycaeus dubius Farran, Proc. Zool. Soc. London, 1911, pp. 292-294, pl. 12, fig. 7; pl. 14, figs. 5-9, 1911.] Found at four stations in the middle and Caribbean regions of the Atlantic and widely scattered over the Pacific. But the gaps in its distribution are so numerous that it was scarcely found anywhere at two stations in succession. It was captured in 19 surface tows, 12 50-meter tows, and 5 100-meter tows. These records show a preference for the two upper tows, especially for the surface tow, but the species was not present in any of the nocturnal surface tows. Originally founded somewhat doubtfully, as its name suggests, on a single female, DISCUSSION OF SPECIES the species was made valid a year later with descriptions and figures of both sexes. Corycaeus flaccus Giesbrecht (Figure 50) [Corycaeus flaccus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 480, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 659-674, pl. 51, figs. 10, 11, 1892.] Found at the first three localities in the Atlantic, in the Caribbean, and in every region of the Pacific, except above 40° north latitude, but with numerous and extensive gaps. It was present in 4 nocturnal surface tows, and in the daytime was taken in ro surface tows, 22 50-meter tows, and 18 100- meter tows, and in the vertical tow from 1ooo meters at station 64. It may be recognized in side view by the small knob projecting from the distal end of the dorsal surface of the genital segment. Corycaeus furcifer Claus [Corycaeus furcifer Claus, Die freilebenden Copepoden, p. 157, pl. 24, 1863.] Found at station 32 in the Caribbean, and, like the pre- ceding species, scattered in every region of the Pacific with numerous and extensive gaps in distribution, but not above 40° north latitude. It was taken in 1 nocturnal surface tow, and in the daytime was present in 3 surface tows, 6 50-meter tows, and 8 100-meter tows. In side view the posterior end of the genital segment carries a dorsal pointed spine. Corycaeus giesbrechti F. Dahl (Figure 37) [Corycaeus giesbrechti F. Dahl, Verhandl. Deut. zool. Ge- sellsch., vol. 4, Munchen, p.-72, 18946. | Not found in the Atlantic plankton, but present in the southeastern and central regions of the Pacific and even more widely scattered than the two preceding species. It was taken once at the surface in the night, and in the daytime was found in 3 surface tows, 3 50-meter tows, and 2 1o0-meter tows. The genital and anal segments are slender and each is twice as long as wide; the caudal rami are of the same length as the anal segment. Corycaeus lautus Dana [Corycaeus lautus Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 37, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1219, 1853; pl. 85, fig. 12, 1855.] Found at the first Atlantic station, at six stations in the Sargasso and Caribbean regions, and in every region of the Pacific except the far north. It was present in 5 nocturnal surface tows, and in the daytime was taken in 1g surface tows, 22 50-meter tows, and 22 roo-meter tows; also taken in the vertical tow from 1000 meters at station 64. This is the longest of all the species of the genus, and the genital seg- ment is but little wider than the anal segment. 181 Corycaeus limbatus Brady [Corycaeus limbatus Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 114, pl. 49, 1883.] Found at four localities in the Atlantic and fairly abundant in the southeastern Pacific, but very scattering elsewhere. It was taken in 5 nocturnal surface tows, and in the daytime in 19 surface tows, 19 50-meter tows, and 20 100-meter tows, an exceptionally uniform vertical distribution. The urosome is one-segmented in the female, slender and tapered evenly both anteriorly and posteriorly; the terminal claw of the second antenna is exceptionally short. In the male the urosome is two-segmented, the genital segment much wider than the anal segment, the latter abruptly narrowed; the terminal claw of the second antenna is much longer. Corycaeus longistylis Dana [Corycaeus longistylis Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 36, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1212, 1853; pl. 85, fig. 5a-d, 1855.] Not found in the Atlantic plankton, but common in the southeastern and central regions of the Pacific. It was cap- tured in 2 nocturnal and 25 diurnal surface tows, 33 50-meter tows, and 30 100-meter tows; also in the vertical tow from 1000 meters at station 64. The urosome of the female is two- segmented, the genital segment nearly twice as wide as the anal segment, the latter abruptly narrowed. The posterior processes of the third thoracic segment reach backward be- yond the posterior margin of the genital segment. Corycaeus lubbockii Giesbrecht (Figure 38) [Corycaeus lubbocki Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 481, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 660, 674; pl. 51, figs. 51, 57, 58, 1892.] Not found in the Atlantic plankton, but present at four stations in the eastern, central, and western parts of the tropical Pacific. It was taken twice in the surface tow, once in the 50-meter tow, and once in the 1oo-meter tow. In the female there is a small knob on the dorsal surface of the genital segment, and in both sexes the anterior margin of the genital segment carries a small medium spine on the ventral surface. Corycaeus minimus F. Dahl (Figure 39) [Corycaeus minimus F. Dahl, Verhandl. Deut. zool. Gesellsch., vol. 4, Munchen, p. 71, 18940.] Found at three stations in the Atlantic and two in the southeastern Pacific. It was present three times in the surface tow, once in the 50-meter tow, and twice in the 100-meter tow. This species is very small, the anal segment is nearly as wide as long, and the caudal rami are twice as long as the anal segment. 182 Corycaeus ovalis Claus [Corycaeus ovalis Claus, Die freilebenden Copepoden, p. 158, 1863. | Found at station 1 in the Atlantic and in widely separated localities of the southeastern, central, and western Pacific. It was present in 8 surface tows, 7 50-meter tows, and 2 100- meter tows. The posterior processes of the fourth thoracic segment are pointed, and the caudal rami are not longer than the anal segment. Corycaeus pacificus F. Dahl [Corycaeus pacificus F. Dahl, Verhandl. Deut. zool. Gesellsch., vol. 4, Munchen, p. 73, 18940. | Not found in the Atlantic plankton, but very irregularly scattered in the southeastern, central, and western Pacific. It was present in 3 nocturnal and 5 diurnal surface tows, 13 50- meter tows, and 13 1oo-meter tows. The posterior processes of the fourth thoracic segment are bluntly rounded, some- times almost circular. Corycaeus pumilus M. Dahl [Corycaeus pumilus M. Dahl, Ergebn. der Plankton-Exped. der Humboldt-Suftung, vol. 2, G. £ 1, Die Copepoden, p. 91, pl. 12, figs. 21-28, 1912.] Found at five Atlantic stations, and well distributed in all regions of the Pacific except the north. Present in 12 noc- turnal and 25 diurnal surface tows, 28 50-meter tows, and 25 100-meter tows, another exceptionally even vertical distribu- tion. In the female the metasome is nearly three times as long as the urosome; in the male the cylindrical posterior part of the genital segment is only one-third as long as wide. Corycaeus robustus Giesbrecht [Corycaecus robustus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 480, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 660, 673; pl. 51, figs. 38, 42, 1892. Not found in the Atlantic plankton, and very irregularly scattered over all regions of the Pacific except the north. It was captured in 1 nocturnal and 6 diurnal surface tows, 9 50-meter tows, and 10 100-meter tows. The genital segment is much swollen laterally and notched near the center of each lateral margin. The processes of the fourth thoracic segment are squarely truncated posteriorly, and the anal segment is much wider than long. Corycaeus speciosus Dana (Figure 41) [Corycaeus speciosus Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 38, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1220, 1853; pl. 86, fig. 1, 1855.] Found everywhere in both oceans, except in the northern parts and at stations 51 to 64 in the South Pacific. Present in 8 nocturnal and 75 diurnal surface tows, 85 50-meter tows, and 66 100-meter tows. The caudal rami are as long as the COPEPODS OF LAST CRUISE OF CARNEGIE urosome in the male, seven-eighths as long and widely diver- gent in the female; genital segment of the female usually arched dorsally. Corycaeus typicus (Kréyer) [Agetus typicus Krdyer, Naturhist. Tidsskr., Kjobenhayn, ser. 2, vol. 2, p. 603, pl. 6, figs. 27-29, 1849.] Found in both oceans except in the northern part and the extreme southern part (stations 59 to 61) of the Pacific. Taken in 7 nocturnal and 27 diurnal surface tows, 41 50- meter tows, and 39 100-meter tows. Processes of the fourth thoracic segment standing up vertically and squarely trun- cated posteriorly, each with a small tooth at the ventral corner. Genus DANODES, new genus Body short and stout; metasome pear-shaped and three- fourths as wide as long; head fused with the first segment, free thorax strongly tapered posteriorly; urosome much shorter than metasome and relatively narrow. First antenna eight-segmented and short; second antenna uniramose, four-segmented; mandible with setaceous palp; lobes of first maxilla very unequal in size; second maxilla and maxilliped unguiculate; mouth a short siphon projecting ven- trally. First four pairs of legs biramose, with three-segmented rami; fifth legs entirely lacking but each replaced by a single small seta. This genus belongs to the siphonostomous Cyclopoida, and is distinguished from the other genera in that group by the eight-segmented first antennae, the uniramose second an- tennae, and the absence of fifth legs. Furthermore, the meta- some is not at all depressed and is without epimeral plates. Genotype. Danodes plumata. Danodes plumata, new species (Figures 57-68) Occurrence. Some thirty specimens, all females, were ob- tained from eleven stations in the eastern and central Pacific, but the species was not found in the Atlantic. Most of the specimens were captured at the surface, but one was found in a 50-meter tow and a few in 2 100-meter tows. Description of female. Metasome pyriform and well arched both dorsally and ventrally, two-thirds as wide as long. Head completely fused with the first thoracic segment, the resultant cephalothorax widest considerably behind its center. Free thoracic segments diminishing rapidly in width backward and without epimeral plates, but the fourth segment has bluntly rounded processes at its posterior corners extending backward and slightly overlapping the fifth segment. Uro- some five-eighths as long and one-sixth as wide as the meta- some, and five-segmented. The fifth thoracic segment is a little more than half the width of the fourth; the anterior part of the genital segment is as wide as the fifth segment, with an oviduct opening on each lateral margin; the posterior part is tapered to the same width as the first abdominal segment, where it joins the latter. The abdomen is three-segmented, the segments diminish- ing considerably in length posteriorly, but only slightly in DISCUSSION OF SPECIES width. Each of the segments of the urosome carries at each posterior corner a fingerlike process which curves inward and overlaps the segment next behind it. Each caudal ramus is as long as the anal segment and two-thirds as wide as long, with four posterior setae and one on the dorsal surface which is attached to an enlarged and projecting base. The head has a small knob at the center of the anterior margin, on a level with the dorsal surface, but no actual rostrum. The first antennae are eightsegmented, the basal segment the shortest, the terminal segment the longest. The second, third, and eighth segments carry numerous setae, and the sixth segment has a slender aesthetask which reaches beyond the tip of the antenna. The second antenna is unt- ramose and four-segmented, the end segment with four setae of which the terminal one is the longest. The mouth tube is short and curved backward, and stands out nearly at right angles to the ventral surface of the head; it is slightly enlarged at the tip, with a radiating flange. The mandibular palp is setaceous, consisting of a narrow cylin- drical joint carrying at its tip a long seta. The first maxilla has the inner lobe well developed and tipped with two stout setae, the outer lobe slightly longer with three setae. The second maxilla and maxilliped are unguiculate; the dactylus of the former is distinctly two-jointed, the terminal part strongly curved and armed on its outer surface at the proxi- mal end with two rows of denticles which join distally and at the point of junction carry a fingerlike process. The dac- tylus of the maxilliped is triarticulate, the terminal part lightly curved and with a single row of cilia on the ventral surface. The first four pairs of legs have three-segmented rami with the spines and setae arranged as follows: first exopod 1-9, I-1, 2-5, endopod 1-1, 0-2, 0-7; second exopod 1-1, 1-1, 3-4, endopod 1-1, 0-2, 0-6; third exopod o-1, 1-1, 3-3, endopod I-1, 0-2, 0-5; fourth exopod o-1, 1-1, 2—3, endopod 1-1, 0-2, o-4. The fifth legs are entirely lacking, but each is replaced by a small seta just inside the posterior corner of the fifth segment. Total length, 1.35 (1.25-1.45) mm; length of metasome, 0.80 mm; width, 0.65 mm; length of urosome, 0.55 mm; width, 0.15 mm. Type. U.S. Nat. Mus. no. 64003. Remarks. This is evidently a surface copepod, but it occa- sionally retires to the 50-meter or even the roo-meter level. The suctorial character of the mouth is suited to a more or less parasitic existence, but all the present specimens were taken while free-swimming and there is nothing to indicate the character or identity of a possible host. Genus DREPANOPUS Brady, 1883 Drepanopus pectinatus Brady [Drepanopus pectinatus Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 77, pl. 24, figs. 1-11, 1883.] A few specimens, including both sexes, were obtained in the 1oo-+meter tow at station 4 in the northern central Atlantic, and this was the only record for the entire cruise. 183 Brady’s (1883, p. 77) original specimens were taken at Ker- guelen Island in the southern Indian Ocean and in the open sea west of it. Giesbrecht (1892, p. 201) reported another species from the South Atlantic and the South Pacific. As far as is known, this is the first record of any species of the genus from the North Atlantic. The species is evidently very rare and is confined to isolated localities. Genus DYSGAMUS Steenstrup and Litken, 1861 Dysgamus atlanticus Steenstrup and Lutken (Figure 32) [Dysgamus atlanticus Steenstrup and Liitken, Kong. Danske Vidensk. Selsk. Skr., ser. 5, Naturhist. og. math. Afd., vol. 5, p. 368, pl. 4, fig. 8, 186r.| A single male was found in the 100-meter tow at station 156 in the central tropical Pacific, in latitude 3° north. In addition to the original description of the species by Steen- strup and Litken (1861, p. 368), Lonnberg (1889, p. 150) published a more detailed and accurate account. But neither of these papers contained a figure showing the pattern of the dorsal surface of the metasome, which is of considerable assistance in identifying the species. Since the Carnegie speci- men showed this pattern rather distinctly, a figure of it is here introduced (fig. 32) for comparison with those of the other two species of the genus already published by the pres- ent author (D. ariommus Wilson, 1907, p. 713, pl. 20, figs. 62-70; D. longifurcatus Wilson, 1923, p. 11, pl. 2, figs. 20- 27). Genus EUAETIDEUS G. O. Sars, 1925 Euaetideus bradyi (A. Scott) [Aetideus bradyi A. Scott, Copepoda of the Siboga Exped., vol. 294, pt. I, p. 38, pl. 5, figs. 1-12, 1909. | Four specimens of this species were found in the eastern Pacific, 1 in a nocturnal surface tow, the other 3 in 100- meter tows. These 3 were negative to light, but the 1 shows that it comes to the surface during the night. It is worthy of note that all the 25 specimens recorded as obtained in the Siboga plankton were taken in vertical tows from various depths, the minimum being 700 meters. This suggests that the species is a deep-water form that would not be found very often within the upper 100 meters during the daytime. Euaetideus giesbrechti (Cleve) [ Aetideus giesbrechti Cleve, Marine Invest. South Africa, vol. 3, pt. 1, Copepoda, p. 185, 1904.] Not found in the Atlantic plankton, and in the Pacific found chiefly in the eastern and southeastern regions. It was taken in 1 50-meter tow and g roo-meter tows, but nowhere at the surface either by day or by night. All the specimens of this species in the Ssboga plankton were taken in vertical tows from considerable depths, with one exception, 5 speci- mens taken at the surface at night. It is thus strongly nega- tive to light but does come to the surface during the night. 184 Genus EUAUGAPTILUS G. O. Sars, 1920 Euaugaptilus filigerus (Claus) [Hemicalanus filigerus Claus, Die freilebenden Copepoden, p. 179, 1863.] A single female was taken in the roo-meter tow at station 55, and this was the only specimen for the entire cruise. The 5 specimens reported by A. Scott (1909, p. 136) from the Siboga plankton were each captured in a separate vertical tow from a considerable depth. Hence we may reasonably infer that the species is nowhere abundant and that it is a deep-water form which very seldom comes into the upper 100 meters. The fact that the two abdominal segments and the caudal rami are of the same length will distinguish the species. Genus EUCALANUS Dana, 1853 The species of this genus were widely scattered in both oceans, but the distribution was markedly gregarious, with teeming colonies separated by long intervals of entire ab- sence from the plankton. The species are dispersed over all the oceans, including the Mediterranean, Arctic, and Ant- arctic, and some of them can be found in every zone, but they are more common in the tropics and southern localities than in the north. They are also present at various depths, from the surface to some of the deepest tows that have been taken. DEPTH IN METERS aH S Cuart 7. Daytime vertical distribution of species of Eucalanus: (1) attenuatus, (2) crassus, (3) elongatus, (4) monachus, (5) mucronatus, (6) subtenuis. A single species was confined to the 50-meter tow, and the other five species were each distributed at all three depths but were least abundant at the surface. Three of these five species were most abundant in the 50-meter tow, one was most abundant in the roo-meter tow, and one was equally abundant in the two deeper tows. These records show that each of the species is more or less negative to light and prefers the greater depths in the daytime, one of them not coming to the surface at all. Eucalanus attenuatus (Dana) [Calanus attenuatus Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 18, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1080, 1853; pl. 75, fig. 2a-m, 1855.| This species was taken once in the Atlantic, and was scat- tered over the entire Pacific, even in the extreme north, but with one very long gap (stations 46 to 67) in its distribution and many shorter ones. It was present in 14 surface tows, 59 50-meter tows, and 48 1oo-meter tows. In view of such wide distribution, it seems strange that this species was not found in the plankton of the Szboga expedition. COPEPODS OF LAST CRUISE OF CARNEGIE Eucalanus crassus Giesbrecht [Eucalanus crassus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 333, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 132, 151, pl. 4, fig. 9; pl. 11, figs. 8, 10, 15, 17, 21, 22, 29, 33, 35, 38; pl. 35, figs. 45 20, 26-28, 1892.] Not present in the Atlantic plankton, and showing in the Pacific a similar long gap from station 45 to 68, though present at stations 55, 57, and 64(&), and another gap from station 134 to 160. It was taken in 2 nocturnal and 3 diurnal surface tows, 25 50-meter tows, and 22 roo-meter tows, and in the vertical tow from 1000 meters at station 64. It can be identified by the very swollen, almost spherical genital seg- ment. Eucalanus elongatus (Dana) [Calanus elongatus Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 18, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1079, 1853; pl. 74, fig. 10, 1855.] Widely scattered in both oceans but quite straggling both in abundance and in continuity of distribution. It was present in 2 nocturnal and ro diurnal surface tows, 69 50-meter tows, and 62 roo-meter tows, and in the vertical tow from 1000 meters at station 64. It is the only species in which the urosome is four-segmented, and often attains a large size. Eucalanus monachus Giesbrecht [Eucalanus monachus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 333, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 132, 151, pl. 11, fig. 37; pl. 35, figs. 5, 14, 33, 36, 1892.] Not obtained in the Atlantic plankton, common in the eastern tropical Pacific (stations 35 to 47 and 71 to 75), but found only three times elsewhere. It was present in 2 noc- turnal and 6 diurnal surface tows, 17 50-meter tows, and 19 1oo-meter tows. It is considerably shorter than the preceding species and the genital segment is wider than long. Eucalanus mucronatus Giesbrecht [Eucalanus mucronatus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 334, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 132, 151, pl. 11, figs. 9, 26, 34; pl. 35, figs. 15, 35. 38, 1892.] Not present in the Atlantic plankton, and in the Pacific virtually limited to the eastern tropical region. It was taken in 2 surface tows, 8 50-meter tows, 8 1o0-meter tows, and in the vertical tow from 1000 meters at station 64. It is easily recognized by the hooklike projection on the forehead, but this is sometimes concealed by being telescoped into the head. Eucalanus subtenuis Giesbrecht [Eucalanus subtenuis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 333, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 132, 150, pl. 11, figs. 23, 423 pl. 35, figs. 9-11, 18, 29, 30, 1892.] Not present in the Atlantic plankton, and found at only six widely separated stations in the Pacific. At each of these DISCUSSION OF SPECIES stations it was confined to the 50-meter tow and barely 2 or 3 specimens were obtained. This is much smaller than the preceding species, and in the male only the left fifth leg is present. In the female the setae of the caudal rami are asym- metrical, being longer and thicker on the right side. Genus EUCHAETA Philippi, 1843 Euchaeta acuta Giesbrecht [Euchaeta acuta Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 246, 262, pl. 16, figs. 6, 10, 14, 18, 21, 27, 39; pl. 37, figs. 47, 48, 52, 1892.] Not found in Atlantic plankton, and although it was widely scattered in the Pacific there are numerous large gaps in its distribution. It was present in 5 nocturnal and 4 di- urnal surface tows, 25 50-meter tows, and 35 100-meter tows; also in the vertical tow from rooo meters at station 64. The left side of the genital segment has an anterior blunt process, which is distinctly notched in dorsal view. Euchaeta hebes Giesbrecht [Euchaeta hebes Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 337, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 246, 263, pl. 15, figs. 29, 30; pl. 16, figs. 3-5, 20, 31, 32, 38, 44; pl. 37, figs. 32, 33, 54, 1892.] Three specimens of this species were obtained in the r100- meter tow at station 35 off the Pacific end of the Panama Canal, and it was found nowhere else in either ocean. As far as is known, this is the first record of the species from the Pacific Ocean. Euchaeta marina (Prestandrea) [Cyclops marinus Prestandrea, Effemeridi sci. e lett. Sicilia, vol. 6, p. 12, 1833.] This is the most widely distributed species of the genus, and was found everywhere in both oceans except the north- ern and southern regions of the Pacific (stations 57 to 68 and I15 to 129). It was present in ro nocturnal and 38 diurnal surface tows, 87 50-meter tows, and 82 roo-meter tows. It was often found equally distributed in all three tows at the same time. Both the last thoracic and the genital segment are asymmetrical in the female, the right side being the larger. Euchaeta spinosa Giesbrecht [Euchaeta spinosa Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 246, 263, pl. 16, figs. 26, 34, 47; pl. 37, figs. 31, 34, 50, 1892.] One specimen was taken in a nocturnal surface tow be- tween stations 63 and 64 in the southeastern Pacific and a few specimens were found in the vertical tow from a depth of 1000 meters at station 64. The former indicates that it does migrate to the surface in the night, and the latter suggests that it remains below 100 meters in the daytime, since it did not appear in the regular tows at station 64. It has been reported by Esterly (1905, p. 159) from the San Diego region, California, by Sharpe (1910, p. 410) from the Cape Cod region on the Atlantic coast, and by other authors 185 from the Mediterranean, Atlantic, Pacific, and Indian oceans. In view of such a wide distribution, it is worthy of note that it did not appear in either the Challenger or the Siboga plankton. Genus EUCHAETOPSIS? Brady, 1918 Euchaetopsis? species Tt is with utmost hesitation that two very juvenile copepods from Atlantic station 1 are considered as possibly represent- ing this genus. The genus is monotypic; only the female of Euchaetopsis haswelli Brady, from the Antarctic Ocean, is known. Genus EUCHIRELLA Giesbrecht, 1888 Euchirella brevis G. O. Sars [Euchirella brevis G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 12, 1905.| Found in the Sargasso and Caribbean regions and scat- tered very irregularly over the entire Pacific with few records at consecutive stations. It was taken in 2 nocturnal and 2 diurnal surface tows, 31 50-meter tows, and 25 100- meter tows. The setae on the enlarged exopod of the second antennae were often exceptionally long, densely plumose, and bright red. These records show the species to be negative to light, with a slight preference for the 50- meter tow. Euchirella curticauda Giesbrecht [Euchirella curticauda Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 336, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 233, 244, pl. 15, figs. 3, 13, 25; pl. 36, figs. 19, 20, 1892.] Found at the first station in the Atlantic and at many stations in the Pacific, long distances apart except in the central region. It was taken in 4 surface tows, 23 50-meter tows, and 11 100-meter tows. The first basipod of the fourth legs has a row of nine to thirteen teeth on its inner margin, and the forehead has a high crest. This species is also nega- tive to light, with more of a preference for the 50-meter tow, and it did not appear in any nocturnal tow. Euchirella intermedia With [Euchirella intermedia With, Copepoda of the Danish Ingolf- Exped., vol. 3, no. 4, p. 124, 1915.] Nine specimens were taken at five Pacific stations, 1 in the 50-meter tow, 5 in the 1oo-meter tow, and 3 in the ver- tical tow from 1000 meters at station 64. This species does not have a crest, and there is a single long, slender spine on the posterior surface of the first basipod of the fourth leg. Its entire absence from the surface tows, both nocturnal and diurnal, shows it to be more negative to light than either of the preceding species. Euchirella messinensis (Claus) [Undina messinensis Claus, Die freilebenden Copepoden, p. 187, 1863.] This species was not present in the Atlantic plankton, and in the Pacific was found once in a 50-meter tow, once in a 186 ro0-meter tow, and in the vertical tow from a depth of 1000 meters at station 64. The genital segment of the female is asymmetrical, with a posterior outgrowth on the left side. The first basipod of each fourth leg has two small spines on the inner margin. Euchirella pulchra (Lubbock) [Undina pulchra Lubbock, Trans. Entomol. Soc. London, n. s., vol. 4, pt. 1, p. 20, 1856.] Found at stations 1 and 27 in the Atlantic and in every region of the Pacific except the north, but at widely separated localities. Taken twice in the surface tow, 7 times in the 50- meter tow, and 7 times in the 100-meter tow. Nine of these records were single specimens and four others were numerals; these correspond well to A. Scott’s (1909, p. 56) records of the Szboga plankton, the largest of which was 6 specimens. These few records indicate that it is more or less negative to light. Euchirella rostrata (Claus) [Undina rostrata Claus, Die Copepoden-Fauna von Nizza, p. 11, pl. 1, fig. 10, 1866.] Found at four stations in the Atlantic, two of which were in the far north, and at six stations in the southeastern Pacific. Taken 5 times in the 50-meter tow, 5 times in the roo-meter tow, and once in the vertical tow from 1000 meters, station 64, but not at all at the surface. Eight of these records consisted of numerals and the other three were designated as rare (7). As far as they go, they indicate a negative phototropism for the species, with limited nocturnal migration. Genus EUTERPINA Norman, 1903 Euterpina acutifrons (Dana) [Harpacticus acutifrons Dana, Proc. Amer. Acad. Arts and Sci., vol. I, p. 153, 1847; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1192, 1853; pl. 83, fig. t1a, b, 1855.] Not present in the Atlantic plankton, but found at four stations in the southeastern Pacific. It was taken once in the surface tow, 3 times in the 50-meter tow, and 3 times in the too-meter tow. Four of these records were single specimens, two more were 2 specimens each, and the seventh was 4 specimens. This harpactid is probably negative to strong light. This species has been reported by Cleve (1900-1901, Pp. 143; 19004, p. 7; 19008, p. 65; as Euterpe acutifrons) from both the North and South Atlantic, and by Esterly (1905, p. 212) as abundant in the Pacific in the San Diego region, California. It was also reported by Sewell (1924, p. 836) from Chilka Lake, a brackish lagoon on the west coast of British India, so that it is not wholly pelagic. Genus FARRANULA (Blake MS) Wilson, 19328 The generic name Corycella proposed by Farran (r1g11, p. 284) for these small cyclopids had been preoccupied by Léger in 1892 for a genus of Protozoa, and Charles H. Blake COPEPODS OF LAST CRUISE OF CARNEGIE suggested in manuscript the name Farranula in place of it. This was adopted and published by the present author (19328, p. 594, footnote). This is essentially a tropical genus, and is widely dis- tributed over the warmer regions of all oceans between latitudes 40° north and 40° south. The species belonging to the genus are among the smallest copepods known, less than a millimeter in length, but they make up in numbers what they lack in size, and often constituted the bulk of the sur- face copepod plankton. DEPTH IN METERS Cuart 8. Daytime vertical distribution of species of Farranula: (1) carinata, (2) concinna, (3) curta, (4) gibbula, (5) gracilis, (6) rostrata. Five species were found somewhat more often at the surface, less often in the 50-meter tow, and least often in the roo- meter tow. The sixth species was found least often in the 50- meter tow, more often in the 100-meter tow, and most often at the surface. According to these Carnegie records, therefore, the species were all positive to light, but the attraction was very weak. The differences in the number of times each species was present, and in its relative abundance, at the three depths were very small. The two most abundant species frequently showed no differences at all in vertical distribution. Farranula carinata (Giesbrecht) [Corycaeus carinatus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 481, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 661, 675, pl. 50, fig. 20, 1892.] The gaps in the distribution of this species were from station 6 to 13 in the North Atlantic, 42 to 45 in the eastern Pacific, 58 to 61 in the South Pacific, and 115 to 128 in the North Pacific. It was taken in 21 nocturnal and 100 diurnal surface tows, 86 50-meter tows, and 72 100-meter tows. It was repeatedly found in two of the tows and often in all three at the same station, and more or less equally distrib- uted. It was recorded as abundant more than a hundred times, and surpassed any other single species of the genus in the number of specimens obtained. Farranula concinna (Dana) (Figure 33) [Corycaeus concinnus Dana, Proc. Amer. Acad. Arts and Sci. vol. 2, p. 39, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1225, 1853; pl. 86, fig. 7a, b, 1855.] Not present in the Atlantic plankton; in the Pacific it was taken in 8 nocturnal and 10 diurnal surface tows, 6 50-meter tows, and 5 r1oo-meter tows. It was recorded but once as abundant and five times as common. Nearly all the speci- DISCUSSION OF SPECIES mens of this species obtained in the Szboga plankton were taken in vertical hauls from considerable depths. Farranula curta (Farran) [Corycella curta Farran, Proc. Zool. Soc. London, rgrr, p. 286, pl. ro, figs. 7-11; pl. 11, figs. 1-6, rgrt.] Found at four Atlantic localities and fairly common in the southeastern and central Pacific. It was present in 17 noc- turnal and 21 diurnal surface tows, 18 50-meter tows, and 17 too-meter tows. It was recorded twelve times as abundant and twelve times as common. The species has been recorded previously from the Indian and Pacific oceans, but not from the Atlantic. Farranula gibbula (Giesbrecht) (Figure 35) [Corycaeus gibbula Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 481, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 661, 675, 1892.] Not found in the North Atlantic (stations 6 to 14), in the South Pacific (stations 58 to 60), in the eastern tropical Pacific (stations 70 to 76), and in the North Pacific (stations 118 to 128), but present everywhere else. It was taken in 22 nocturnal and 76 diurnal surface tows, 41 50-meter tows, and 29 roo-meter tows. It was recorded twenty-one times as abundant and thirty-eight times as common. As far as is known, the species is here reported from the Atlantic for the first time. Farranula gracilis (Dana) (Figure 34) [Corycaeus gracilis Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1207, 1853; pl. 85, fig. 1a-d, 1855.] Found at three Atlantic localities, and in the Pacific chiefly confined to the southeastern region. It was present in 13 nocturnal and 21 diurnal surface tows, 11 50-meter tows, and 14 100-meter tows. It was recorded three times as abun- dant and nine times as common, but on the other hand twenty records were numerals. Farran (1929, p. 296) has reported it as common in the tropical and north temperate Atlantic as well as in the South Pacific. Farranula rostrata (Claus) [Corycaeus rostratus Claus, Die freilebenden Copepoden, p. 157, pl. 28, 1863.] This was the most abundant species next to cariata, and was present in both oceans except in the far north and all but two stations in the extreme south. It was taken in 32 nocturnal and 79 diurnal surface tows, 61 50-meter tows, and 61 100-meter tows. It was recorded forty-five times as abundant and sixty-eight times as common. Like carinata, this species was repeatedly found equally distributed in two or even all three tows at the same time. It was reported by Farran (1929, p. 297) as scarce in the Atlantic but common off New Zealand in the South Pacific. 187 Genus GAETANUS Giesbrecht, 1888 Gaetanus armiger Giesbrecht [Gaetanus armiger Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 335, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 219, 224, pl. 14, figs. 19, 22, 26, 28, 29; pl. 36, figs. 2, 4, 1892.] Found only in the Pacific, at station 35 in the roo-meter tow and at station 64 in the vertical tow from a depth of tooo meters. In the former a single specimen and in the latter 4 specimens were obtained. This suggests that the species may have been present in other localities but that the regular tows were not deep enough to reach it. However, one of the two specimens obtained in the Siboga plankton was captured at the surface in the daytime. Gaetanus kruppii Giesbrecht [Gaetanus kruppii Giesbrecht, Mittheil. aus der Zool. Stat. zu Neapel, vol. 16, p. 202, pls. 7, 8, 1903.] The identification of the single immature male from the vertical tow from 1000 meters at Pacific station 64 off the coast of Chile (latitude 31° 54’ south, longitude 88° 17’ west) should perhaps be considered provisional. From the manner in which the haul was made, it is impossible to say at which level the specimen was captured between 1000 meters and the surface. Otherwise, this species has previ- ously been recorded from the North and South Atlantic, the Mediterranean, and the Indian Ocean. Gaetanus latifrons G. O. Sars [Gaetanus latifrons G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 11, 1905.] A single female was obtained in the 1oo-meter tow at station 137, and this was the only record for the cruise. The fact that only a single specimen of this species was found in the Szboga plankton, although the majority of the tows started well below roo meters, would suggest that the species is not abundant anywhere or at any depth. Sars (1925, p. 57) and With (1915, p. 108) have both recorded this species from the North Atlantic as well as from the Pacific Ocean. Gaetanus miles Giesbrecht [Gaetanus miles Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 335, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 219, 224, pl. 14, figs. 21, 24, 25, 27, 30; pl. 36, figs. 1, 3, 1892.] Found at three widely separated Pacific stations, in the r00-meter tow at stations 37 and 152 and in the vertical tow from 1000 meters at station 64. As suggested for armiger, this species may have been present elsewhere below the regular tows, as it is known to be well distributed in both oceans. It is easily recognized by the spine on the forehead and the exceptional length of the first antennae. It has also been reported by Sars (1925, p. 54) and With (1915, p. 107) from the North Atlantic, and by Cleve (1904, p. 191) from the South Atlantic. 188 Gaetanus minor Farran [Gaetanus minor Farran, Ann. Rept. Fisheries, Ireland, 1902- 03, pt. 2, app. 2, p. 34, pl. 5, figs. 1-11, 1905. This species was taken in a nocturnal surface tow between stations 35 and 36 and in the vertical tow from a depth of 1000 meters at station 64. The former proves that the species migrates to the surface in the night; the latter suggests that the regular tows were not deep enough for this species in the daytime. In support of the latter suggestion, all the Siboga specimens were taken in vertical hauls from considerable depths. Genus GAIDIUS Giesbrecht, 1895 Gaidius affinis G. O. Sars [Gaidius affinis G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 9, 1905.] One specimen of this species was found in the vertical tow from rooo meters at station 64 in the southeastern Pacific. It is smaller than brevispinus but larger than tenuispinus. It is probably more widely distributed than this single locality would indicate, but stays below 100 meters in the daytime. Sars (1905, p- 9; 1925, P- 47) reported this species from both the Atlantic and the Pacific oceans in vertical hauls from depths of 1500 to 4800 meters. Gaidius brevispinus G. O. Sars [Gaidius brevispinus G. O. Sars, Norwegian North Polar Exped., 1893-1896, Sci. res., vol. 5, Crustacea, p. 68, pl. 19, 1900. | A few specimens were found in the 1o0-meter tow at station 8 in the Atlantic, and the species was found nowhere else during the cruise. This is a boreal species, and has been reported from the Arctic Ocean and the North Atlantic. All Sars’ (1903, p. 162; 1925, p. 48) specimens were taken in vertical hauls from depths of 1700 to 2000 meters. Gaidius tenuispinus (G. O. Sars) [Chiridius tenuispinus G. O. Sars, Norwegian North Polar Exped., 1893-1896, Sci. res., vol. 5, Crustacea, p. 67, pl. 18, 1900. | This species was found in the southeastern and northern parts of the Pacific. It was taken twice in the 50-meter tow, 5 times in the 1oo-meter tow, and once in the vertical tow from roo0o meters at station 64. The records are all expressed in numerals, indicating that the species is nowhere abun- dant. Since it did not occur anywhere at the surface, it is evidently negative to light. It was reported by Sars (1903, p. 162; 1925, p. 46) from several localities in the North Atlantic and even in the Arctic Ocean, and is a boreal form. Genus HALOPTILUS Giesbrecht, 1898 This genus was well scattered over both oceans, but showed several large gaps in distribution. No species was found in the first thirteen stations of the Atlantic, or at stations 58 to 68 in the Pacific (except at station 67 and in the ro00-meter haul at station 64), or at stations 82 to 93 and COPEPODS OF LAST CRUISE OF CARNEGIE 117 to 130. All the species, without exception, were confined to the two deeper tows, especially the 1oo-meter tow. The fact that no species of this genus appeared in any of the nocturnal surface tows would suggest that the genus does not take part very often in the vertical migrations. DEPTH IN METERS Cuart 9. Daytime vertical distribution of species of Haloptilus: (1) acutifrons, (2) angusticeps, (3) longicornis, (4) ornatus, (5) oxycephalus, (6) plumosus, (7) spiniceps. One species was confined to the 50-meter tow, two to the 1oo-meter tow, and the other four appeared only in the two deeper tows, with the greater abundance in the 100-meter tow. This is a more uniform vertical distribution than that of some of the other genera, and all the species react similarly to their environment. Haloptilus acutifrons (Giesbrecht) [Hemicalanus acutifrons Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 384, 398, pl. 3, fig. 11; pl. 27, figs. 4, 12, 18, 26; pl. 42, figs. 12, 20, 1892.] This species was present in 3 50-meter tows and in 14 100-meter tows, and in the vertical tow from 1000 meters at station 64, all in the Pacific Ocean. With a single exception, every one of the abundance records is a numeral, and twelve of them were single specimens. In this connection it is worthy of note that the species did not appear at all in the Siboga plankton or in the /ngo/f plankton. Its scarcity in the Carnegie plankton, therefore, can hardly be due to the fact that the tows (with one exception) did not descend below roo meters. It has been recorded by Sars (1925, p. 250) and Farran (1929, p. 267) from the North Atlantic and the Arctic Ocean. Haloptilus angusticeps G. O. Sars [Haloptilus angusticeps G. O. Sars, Bull. Inst. océanogr. Monaco, no. tor, p. 20, 1907.| A single female was taken in the 50-meter tow at station 116 in the western Pacific off the coast of Japan, and this was the only record for the cruise. Like the preceding species, this one did not appear in the lists of any of the plankton expeditions, but has been reported by Sars (1925, p. 246) from the North Atlantic and the Mediterranean. The species is thus very rare, and this Carnegie record is the first one from the Pacific Ocean. Haloptilus longicornis (Claus) |Hemicalanus longicornis Claus, Die freilebenden Copepoden, p. 179, pl. 29, 1863. | This is the most numerous and widely distributed species of the genus, and was found everywhere in the temperate and tropical regions of both oceans. It was present in 23 50- DISCUSSION OF SPECIES meter tows, 70 100-meter tows, and the vertical tow from 1000 meters at station 64, but not in any of the surface tows. The distal half of each first antenna is very slender and looks fragile, but it must be exceptionally tough, since it usually remains intact in the preserved specimens although the two antennae are often intricately entangled with each other and with the other appendages. The absence of the species from all nocturnal surface tows indicates that it does not take part very often in the upward migration at night. The northern boundary of the species as given by Giesbrecht (1892, p. 384) and Sars (1925, p. 240) (latitude 26° north) is extended by these Carnegie records to latitude 34° north in the Pacific and to 42° north in the Atlantic. Haloptilus ornatus (Giesbrecht) [Hemicalanus ornatus Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 384, 399, pl. 27, figs. 16, 17, 25; pl. 2, figs. 2, 27, 28, 1892.] This species was found at nine Atlantic and nine Pacific stations, the Atlantic localities being in the Sargasso and Caribbean regions, the Pacific localities widely scattered. It Was present in 4 50-meter tows and 14 100-meter tows, and was recorded as common five times. It was originally taken in the Mediterranean, but has been reported by several authors from the Atlantic and Pacific oceans. Only 2 speci- mens were obtained in the Sboga plankton, both in vertical hauls from depths of 700 to goo meters. Haloptilus oxycephalus (Giesbrecht) [Hemicalanus oxycephalus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. $13, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 384, 398, pl. 42, figs. 7, 16, 23, 1892.] A single specimen of this species was found in the 100- meter tow at each of two stations, 70 and 74, in the eastern tropical Pacific, and it has also been reported from the trop- ical Pacific by Giesbrecht (1892, p. 384). Yet Farran (1929, p. 268) has recorded it from both sides of the Antarctic Circle in the South Pacific, so that it cannot be considered as exclusively tropical. Nearly all the specimens previously ob- tained were taken in vertical hauls from deep water, and the species was nowhere abundant. Haloptilus plumosus (Claus) [Hemicalanus plumosus Claus, Die freilebenden Copepoden, p. 178, pl. 28, fig. 12; pl. 29, figs. 4-7, 1863.] This species was found at one Atlantic station and at eighteen widely separated Pacific stations, and in them was strictly confined to the 100-meter tow, though present in the vertical tow from 1000 meters at station 64. Its failure to appear above the roo-meter level suggests that it is bathy- pelagic, and this conclusion is supported by the fact that all the specimens previously reported have been captured at a depth varying from 400 to 3000 meters. As far as all the records show, these 1o0o-meter tows are the nearest to the surface it has ever been taken. 189 Haloptilus spiniceps (Giesbrecht) [Hemicalanus spiniceps Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 384, 399, pl. 27, figs. 5, 20, 35, 40; pl. 42, figs. 3, 8, 10, 11, 21, 25, 1892.| This species, like plamosus, was found at a single Atlantic station and at widely separated localities in the Pacific. It was taken in 13 50-meter tows and 16 100-meter tows, but 80 per cent of the abundance records were numerals. Hence, although fairly widespread, the species is nowhere abundant, and its complete absence from the surface at night as well as in the daytime indicates infrequent nocturnal migrations. The characteristic spiny projection from the forehead is often found telescoped into the head in preserved material, making the identification of the species difficult. Genus HETERAMALLA G. O. Sars, 1907 Heteramalla dubia (T. Scott) [Amallophora dubia T. Scott, Trans. Linn. Soc. London, ser. 2, Zool., vol. 6, pt. 1, p. 55, pl. 4, figs. 1-18, 1894.] A few specimens were obtained in the roo-meter tows at stations 56 and 153 in the southeastern and central Pacific, and these were the only localities during the cruise. The species was originally reported by T. Scott (1894, p. 55) from the Gulf of Guinea and included males only. A female was afterward found in the Siboga plankton and described by A. Scott (1909, p. 86), and both sexes were captured in the North Atlantic during the Monaco expeditions and described by Sars (1925, p. 142). All these specimens were taken in vertical hauls from depths of 1500 to 5000 meters. Genus HETERORHABDUS Giesbrecht, 1898 This is a deep-water genus, and with a single exception none of its species was found at the surface, whereas two of them were confined to the single 1ooo-meter haul at station 64. The genus was fairly well distributed in both oceans, however, especially in the Pacific, a fact which is the more noteworthy in that most of the specimens hitherto reported came from depths considerably below 100 meters. It belongs chiefly to the temperate and tropical zones, although speci- mens have been obtained from both polar oceans. The single specimen of the species papilliger taken in a nocturnal sur- face tow indicates very meager participation in the upward migrations at night. The genus may be easily recognized by the asymmetry of the caudal rami and the excessive length of one seta on the left ramus. Heterorhabdus abyssalis (Giesbrecht) [Heterochaeta abyssalis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 812, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 373, 382, pl. 19, fig. 4; pl. 20, figs. 29, 30, 1892.] Three specimens were taken in the vertical tow from 1ooo meters at station 64. This species has been obtained only from considerable depths, as its name implies, and hence it would not be likely to occur in the Carnegie plankton except 190 in this one deep tow. It has been reported by Cleve (1904, p. 191) from the South Atlantic, but Giesbrecht’s (1898, p. 116) record from the North Atlantic can hardly be ac- cepted. Heterorhabdus compactus G. O. Sars [Heterorhabdus compactus G. O. Sars, Rés. camp. sci. Albert de Monaco, no. 69, p. 226, 1925; pl. 62, figs. 1-8, 1924.] A single female of this species was captured in the vertical tow from 1000 meters at station 64. Farran (1929, p. 267) has recorded this species from two deep vertical tows in the Antarctic south of the Pacific. This deep tow at station 64 came out of the Peruvian or Antarctic current, where the temperature was only 3°8 C at 1000 meters depth. All the specimens obtained by Sars (1925, p. 226) were taken in vertical hauls from depths of 1500 to 4000 meters. Heterorhabdus norvegicus ( Boeck ) [Heterochaeta norvegica Boeck, Forhandl. Vidensk. Selsk. Christiania, vol. 14, p. 40, 1872.] Not present in the Pacific plankton; a few specimens, in- cluding both sexes, were taken in the 50-meter tow at station 11 in the North Atlantic. It was recorded by Sars (1900, Pp. 79; 1902, p. 118; 1925, p. 226) from Nansen’s polar ex- pedition and from Greenland, and is evidently a boreal species. In the open ocean it would probably stay well below roo meters and hence escape the Carnegie tows. This is one of the largest species of the genus, and its size aids materially in its identification. Heterorhabdus papilliger (Claus) (Figure 56) [Heterochaeta papilligera Claus, Die freilebenden Copepoden, p. 182, pl. 32, 1863.] This is the most abundant species of the genus; it was found at three of the Atlantic stations and in all the regions of the Pacific, except far north. But a large majority (46) of the abundance records were numerals, hence it was nowhere at all common. It was present in 4 diurnal surface tows, 15 50-meter tows, and 42 100-meter tows, and 1 specimen in the vertical tow from rooo meters at station 64. It is probably negative to strong light. It was also taken in one of the noc- turnal surface tows, and therefore sometimes migrates to the surface at night. The blunt papilla on the forehead and the fifth legs of the male are distinguishing characters. Farran (1929, p. 265) said this was the most frequent species of the genus in the Terra Nova plankton. Heterorhabdus spinifrons (Claus) [Heterochaeta spinifrons Claus, Die freilebenden Copepoden, p. 183, pl. 32, 1863.] This species was second in abundance; it was not present in the Atlantic plankton and was most frequent in the southeastern and central regions of the Pacific. It was taken in 6 50-meter tows and 18 1o0-meter tows, but did not appear at the surface. The papilla on the forehead is pro- duced into a sharp point or spine, which distinguishes it from the other species. This is another of the larger species, COPEPODS OF LAST CRUISE OF CARNEGIE and was taken at the surface off New Zealand in the south- ern Pacific by the Terra Nova expedition. Genus HETEROSTYLITES G. O. Sars, 1920 Heterostylites longicornis (Giesbrecht) [Heterochaeta longicornis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 812, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 373, 383, pl. 19, fig. 73 pl. 20, figs. 14, 21, 25, 26; pl. 39, fig. 44, 1892.] This species was not present in the Atlantic plankton and was found but once (station 132) outside the southeastern Pacific. A solitary specimen was taken in a 50-meter tow; all the others were taken in roo-meter tows, except I specimen in the vertical tow from rooo meters, station 64, hence the species is negative to light. The first antennae reach eight or ten segments beyond the tips of the caudal rami and thus identify the species. The species has been reported from the temperate and tropical Atlantic by Giesbrecht (1898, p. 116) and Sars (1925, p. 238). Genus LABIDOCERA Lubbock, 1853 This is a tropical and temperate genus, and was not found north of latitude 50° north in the Atlantic or 40° in the Pacific, nor south of latitude 35° south in the Pacific. It is also a surface genus, and all the species were found either entirely or almost entirely in the surface tow. The species detruncata was the only one at all widely distributed, all the others being very local in occurrence. DEPTH IN METERS Cuart 10. Daytime vertical distribution of species of Labi- docera: (1) acuta, (2) acutifrons, (3) detruncata, (4) nerii, (5) wollastont. Two of the species were confined to the surface; the other three appeared at all three depths but were much more abundant at the surface. This diversity in vertical distribution leads to the conclusion that the positive phototropism of species I and 5 is considerably stronger than that of the other three species. In these three species, furthermore, the difference in phototropism is greater in the upper 50 meters than it is between 50 and 100 meters. Attention should be called, however, to the fact that the labidoceran plankton at the surface usually contained a large number of developmental stages, whose reaction to light might change materially on reaching maturity. Labidocera acuta (Dana) (Figure 51) [Pontella acuta Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 30, 1849.] [Pontellina acuta Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, pp. 1150-1152, 1853; pl. — 80, fig. 12a-c, 1855.] Not present in the Atlantic plankton, although it was re- ported from both the North and South Atlantic by Gies- DISCUSSION OF SPECIES brecht (1898, p. 135). It was taken in 4 nocturnal and 2 diurnal surface tows in the southeastern Pacific, and appar- ently stays at the surface throughout the entire 24 hours. Head with median crista which is curved anteriorly into a hook; abdomen and caudal rami symmetrical. It was found in more than fifty of the Szoga plankton collections, in one of which the number of specimens obtained was 200 and in another 440, showing that this species, like detruncata, 1s more or less gregarious. Labidocera acutifrons (Dana) (Figure 52) [Pontella acutifrons Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 30, 1849.] [Pontellina acutifrons Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, pp. 1149, 1150, 1853; pl. 80, fig. 11a—h, 1855.| Not present in the Atlantic plankton, but found in the southeastern and central Pacific. Taken in 7 diurnal surface tows, I 50-meter tow, and 1 roo-meter tow, also recorded as common in one of the nocturnal surface tows. Head with a median crista which is not hooked; abdomen and caudal rami quite asymmetrical. This species has been reported from the tropical and temperate Atlantic, both north and south of the equator, by Giesbrecht (1892, p. 445) and Sars (1925, P. 354)- Labidocera detruncata (Dana) (Figures 53, 69) [Pontella detruncata Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 29, 1849.] [Pontellina detruncata Dana, U. S. Exploring Exped., 1838- 1842 (Wilkes), vol. 14, pt. 2, Crustacea, pp. 1143-1145, 1853; pl. 80, fig. 74-7, 1855.| Not found in the Atlantic plankton, but the most abun- dant species of the genus in the Pacific, and found every- where except in the northern and southern parts, stations 52 to 70 and 116 to 128. It was taken in 6 nocturnal and 68 diurnal surface tows, 11 50-meter tows, and 7 100-meter tows. It is a surface species, and both adults and development stages often swarm at the surface and constitute the bulk of the surface copepods. The females are easily identified by the peculiar asymmetry of the urosome and the males by the structure of the fifth legs. It was reported by Brady (1883, p. 90) from both the North and South Atlantic. Labidocera nerii (Kr¢yer) (Figure 86) [Pontia nerit Krdéyer, Naturhist. Tidsskr., Kjobenhavn, ser. 2, vol. 2, p. 600, 1849.] Found at four stations in the Atlantic and three in the Pacific, all widely separated. It was present in 4 surface tows, 2 50-meter tows, and 2 100-meter tows. It can be distin- guished from the other species by the structure of the fifth legs. As far as is known, this is the first record of the species from the Pacific Ocean, the four stations being in the tropics. 1gI Labidocera wollastoni (Lubbock) (Figure 95) [Pontella wollastoni Lubbock, Ann. and Mag. Nat. Hist., ser. 2, vol. 20, p. 406, pls. 10, 11, 1857.] Not present in the Pacific plankton, but taken at two of the Atlantic localities in the surface tow. The specimens were not fully developed, but the fifth legs showed the dis- tinctive structure of this species. Apparently it has never been reported from the Pacific Ocean. Genus LOPHOTHRIX Giesbrecht, 1895 Lophothrix frontalis Giesbrecht [Lophothrix frontalis Giesbrecht, Bull. Mus. Comp. Zodl., Harvard Coll., vol. 25, no. 12, p. 254, pl. 2, figs. 1-5, 9-12, 1895. | A single specimen was captured in the vertical tow from 1000 meters at station 64. This is a deep-water species and probably has a much wider distribution than the solitary capture would suggest, since this was the only time the tow nets went below roo meters. The prominent median crest on the forehead and the structure of the fifth legs identify the species. It was reported as common in deep hauls off the California coast by Esterly (1906, p. 65). Lophothrix humilifrons G. O. Sars [Lophothrix humilifrons G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 22, 1905. | A single specimen was captured in the same vertical tow as the preceding species. This is another deep-water form and, like frontalis, is probably more widely distributed at depths below roo meters. It can be distinguished by its ob- tusely rounded forehead, which shows no trace of a median crest. This species has been reported only by Sars (1925, p. 166), who found it common in deep hauls in the tem- perate Atlantic. Genus LUBBOCKIA Claus, 1863 Lubbockia aculeata Giesbrecht [Lubbockia aculeata Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. I, p. 477, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 606, 611, pl. 48, figs. 3, 9, 13, 17, 20, 1892.] Found at a single station (15) in the Atlantic and at twenty-one widely separated localities in the Pacific. It was taken in 1 nocturnal surface tow, 13 diurnal 50-meter tows, and 15 roo-meter tows. It was not present at the surface in the daytime and is therefore negative to light, but migrates to the surface sometimes at night. This species is longer and more slender than squillimana, and the posterior margins of the urosome segments are fringed with small spines. All but 2 of the specimens taken in the Szboga plankton were cap- tured in vertical hauls from depths of 900 to 1500 meters, and Wolfenden’s (1911, p. 363) single record was from a vertical haul from a depth of 3000 meters. 192 Lubbockia squillimana Claus [Lubbockia squillimana Claus, Die freilebenden Copepoden, p. 164, pl. 25, figs. 1-5, 1863.] Well distributed in the Sargasso and Caribbean regions and in all the regions of the Pacific except the north (stations 116 to 132) and the south (stations 57 to 65). It was present in I nocturnal surface tow, 30 50-meter tows, and 33 100- meter tows, but did not appear at all in a diurnal surface tow. It is shorter and stouter than aculeata, and the posterior margins of the urosome segments are smooth. In the Siboga plankton it was taken once in a nocturnal surface tow. Genus LUCICUTIA Giesbrecht, 1898 Two of the species of this genus were very widely dis- tributed, one was confined to a single station, another was found at two stations only, and a fifth was rather rare but found in both oceans. All six of the species are practically confined to the two deeper tows and appear at the surface not at all or in such small numbers as to be negligible. a is) is} DEPTH IN METERS S Ss Cuart 11. Daytime vertical distribution of species of Lucicutia: (1) bicornuta, (2) clausti, (3) curta, (4) flavicornis, (5) grandis, (6) longicornis. One of the species was confined to the 100-meter tow, one appeared only in the two deeper tows, one was taken at the surface and roo meters only, and the other three were most abundant in the 1oo-meter tow. Lucicutia bicornuta Wolfenden [Lucicutia bicornuta Wolfenden, Deut. Stidpolar-Exped., 1901- 1903, vol. 12, Zool., vol. 4, p. 321, fig. 63a-c, 1911.] Not found in the Atlantic plankton, but obtained at three widely separated stations in the Pacific. The total number of specimens was 5, 3 of which were taken in the 100-meter tow and 2 in the 50-meter tow. Hence, so far as these few individuals are concerned the species is negative to light. It is evidently not abundant anywhere, since the majority of the specimens thus far recorded have been single indi- viduals. It was first reported and has since been found chiefly in the temperate Atlantic. Lucicutia clausii (Giesbrecht) (Figure 54) [Leuckartia clausti Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 812, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 359, 367, pl. 19, figs. 5, 6, 12- 14, 24, 26, 27; pl. 38, fig. 37, 1892.] This species was well distributed in both oceans except in the northern regions and the extreme southern part of the Pacific. It was present in 7 nocturnal and 2 diurnal surface COPEPODS OF LAST CRUISE OF CARNEGIE tows, 28 50-meter tows, and 73 100-meters tows, and in the vertical tow from 1000 meters at station 64. It is negative to light and stays below the surface in the daytime, but migrates upward at night. Six of the 8 specimens in the Siboga plankton were taken in vertical hauls from 1000 to 2000 meters. Lucicutia curta Farran (Figure 85) [Lucicutia curta Farran, Ann. Rept. Fisheries, Ireland, 1902-03, pt. 2, app. 2, p. 44, pl. 12, figs. 1-7, 1905.] : Two specimens were obtained from the surface tow at station 54 and 2 from the 1oo-meter tow at station 74, and these were the only records for the cruise. This species was originally obtained in deep water off the coast of Ireland and later in the Antarctic, and it is possible that it remains below the roo-meter level in the daytime. But it evidently migrates to the surface at night, and under favorable conditions may stay long enough to be taken in the early forenoon. Lucicutia flavicornis (Claus) [Leuckartia flavicornis Claus, Die freilebenden Copepoden, p. 186, pl. 32, 1863.] This was the most abundant and most widely distributed species of the genus, but was not found in the extreme north of the Atlantic or in the extreme south of the Pacific. It was present in 2 nocturnal and 3 diurnal surface tows, 30 50- meter tows, and 79 100-meter tows, and in the vertical tow from 1000 meters, station 64. It is thus negative to light; each of the daytime surface records was a single specimen, whereas it was often abundant in the deeper tows. Lucicutia grandis (Giesbrecht) (Figure 87) [Leuckartia grandis Giesbrecht, Bull. Mus. Comp. Zoodl., Harvard Coll., vol. 25, p. 258, pl. 4, fig. 4, 1895.] A few specimens of this species were found in the roo- meter tow at station 31 in the Caribbean Sea, and this is the only record for the cruise. The species, however, has been reported by Sars (1925, p. 208) and Wolfenden (1911, p. 315) as quite abundant in the temperate Atlantic at considerable depths, and also from the tropical Pacific by Giesbrecht. Farran (1929, p. 264) obtained 7 specimens in the Antarctic in a vertical haul from 1000 meters. The large pad on the ventral surface of the genital segment is a distinctive char- acter. Lucicutia longicornis (Giesbrecht) [Leuckartia longicornis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. $13, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 359, 367, pl. 19, figs. 7, 30; pl. 38, fig. 39, 1892.] This species was found at three localities in the Sargasso region and was widely scattered in the Pacific at stations long distances apart. It was captured in 1 nocturnal and 2 diurnal surface tows, 3 50-meter tows, and 12 100-meter tows, and in the vertical tow from 1000 meters, station 64. Hence, though staying in deeper water during the daytime, DISCUSSION OF SPECIES it sometimes migrates to the surface at night. This species has apparently been recorded only by Giesbrecht (1892, p- 359) and Wolfenden (1911, p. 323). Genus MACROSETELLA A. Scott, 1909 Macrosetella gracilis (Dana) [Setella gracilis Dana, Proc. Amer. Acad. Arts and Sci., vol. 1, p. 154, 1847; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1198, 1853; pl. 84, fig. 3a-g, 1855.] Found at nearly every station in the Atlantic south of 50° north latitude, and in every region of the Pacific with numerous gaps in the distribution. It was captured in 11 nocturnal and 42 diurnal surface tows, 55 50-meter tows, and 49 100-meter tows. It was often also evenly distributed at all three depths at the same time. Hence the vertical dis- tribution indicates indifference to weak light, with the possi- bility of becoming negative as the light increases in strength. All the developmental stages from nauplius to adult were present in several of the surface tows. Macrosetella oculata (G. O. Sars) [Setella oculata G. O. Sars, Bull. Inst. océanogr. Monaco, no. 323, p. 13, pl. 7, 1916.] This species is more tropical than gracilis and very much less abundant. It was found in both oceans in 2 nocturnal and 4 diurnal surface tows, 12 50-meter tows, and 17 100- meter tows. The four daytime surface records were single specimens, except one (7), so that the species is negative to light. The bright blue of the body and the red eyes usually retain their color in formalin, making identification easy. Most of the records of this species consist of single indi- viduals, and no developmental stages were found. Genus MECYNOCERA I. C. Thompson, 1888 Mecynocera clausi I. C. Thompson [Mecynocera clausi 1. C. Thompson, Jour. Linn. Soc. London, Zool., vol. 20, p. 150, pl. 11, 1888.] Found everywhere in both oceans except the northern regions. It was taken in 4 nocturnal and 23 diurnal surface tows, 98 50-meter tows, and go roo-meter tows, and in the vertical tow from 1000 meters, station 64. It was usually present in both deeper tows at the same time, and rarely in all three, hence its vertical distribution would indicate that it is indifferent to weak light but negative to strong light. Its small size, exceptionally long first antennae, and swollen genital segment are distinguishing characters. Genus MEGACALANUS Wolfenden, 1904 Megacalanus longicornis (G. O. Sars) [Macrocalanus longicornis G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 7, 1905.] This large species was well distributed in both oceans, especially the tropical parts. It was present in 8 nocturnal and 2 diurnal surface tows (in each of the latter a single 193 specimen), 39 50-meter tows, and 34 1oo-meter tows, and in the vertical tow from 1000 meters at station 64. It is, accord- ingly, negative to light, and migrates to the surface during the night. The first legs are armed with a stout curved spine or claw at the inner distal angle of the second basipod. Megacalanus princeps (Brady) [Calanus princeps Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 24, Copepoda, p. 36, pl. 6, figs. 3-7, 1883.] This species is larger than the preceding and was also found in both oceans, but in much smaller numbers. It was taken in 1 daytime surface tow, 5 50-meter tows, and 5 100- meter tows, but did not appear in any of the nocturnal surface tows. It was also in the vertical tow from 1ooo meters at station 64. Sars (1925, p. 14) has reported this copepod in deep-water hauls in both oceans, and Brady (1883, p. 36) found it in the Challenger plankton from the North Atlantic at a depth of 1250 fathoms. Genus MESOCYCLOPS G. O. Sars, 1914 Mesocyclops leuckarti (Claus) [Cyclops leuckarti Claus, Arch. f. Naturgesch. (Berlin), vol. 23 (1), p. 35, pl. 1, fig. 4; pl. 2, figs. 13, 14, 1857.] A few specimens of this well known species were found in a lagoon or pond on Penrhyn Island in the tropical Pacific. The water must have been at least brackish if not saline, since the other nine species taken at this locality were all typical marine forms. Genus METIS Philippi, 1843 Metis jousseaumei (Richard) [Ilyopsyllus jousseaumer Richard, Bull. Soc. zool. France, vol. 17, p. 69, 1892.] Two females of this minute harpactid were present in a surface tow taken at the ship’s anchorage at Hanga Roa, Easter Island. The anchorage must have been in an open roadstead, since this was the only species to give an idea of the proximity of land, and all the other species were pelagic forms. Genus METRIDIA Boeck, 1865 Metridia brevicauda Giesbrecht [Metridia brevicauda Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 24, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 340, 346, pl. 33, figs. 5, 10, 11, 14, 21, 26, 32, 1892.] Not found in the Atlantic plankton, and in the Pacific practically confined to a few localities in the southeastern region. It was taken in 1 nocturnal surface tow, 2 50-meter tows, and 6 roo-meter tows. These few specimens were negative to light but showed occasional migration to the surface at night. All the specimens (22) in the Siboga plankton were captured in vertical hauls from depths of 750 to 1500 meters. The species has been reported from the South Atlantic by Cleve (1904, p. 192). Toe Metridia curticauda Giesbrecht [Metridia curticauda Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 24, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 340, 346, pl. 32, fig. 7; pl. 33, figs. 4, 15, 33, 1892.] Not found in the Pacific plankton and confined to two localities in the eastern Atlantic. It was present in 1 noc- turnal and 1 diurnal surface tow and 1 100-meter tow. Farran (1929, p. 259) reported numerous specimens in the Antarctic from depths of 600 meters or more, so this is apparently a deep-water form, which does not often rise to the roo-meter level in the daytime. Metridia longa (Lubbock) [Calanus longus Lubbock, Ann, and Mag. Nat. Elist, sex: 25 vol. 14, p. 127, pl. 5, fig. 10, 1854.] Found at four Atlantic and six Pacific localities, the latter chiefly in the western region. It was captured in 3 nocturnal surface tows, 3 50-meter tows, and 7 100-meter tows, and in the vertical tow from 1000 meters, station 64; hence it is negative to light and migrates to the surface in the night. It has been reported by Sars (1925, p. 198) from the Arctic Ocean as far north as Spitzbergen and seems to be a more or less boreal form. Metridia lucens Boeck (Figure 70) [Metridia lucens Boeck, Forhandl. Vidensk. Selsk. Christiania, p. 238, 1865.] Found at a single Atlantic station (11) and at fifteen Pacific stations, chiefly in the northern part above latitude 40° north. It was present in 7 50-meter tows and 10 100- meter tows, and in the vertical tow from 1000 meters at station 64, but was not found at the surface. The fifth legs of the female are three-segmented, each end segment having three terminal setae and one on the outer margin. Metridia princeps Giesbrecht (Figure 102) [Metridia princeps Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 24, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 340, 346, pl. 32, fig. 21; pl. 33, figs. 3, 18, 35, 40, 1892.] Not found in the Atlantic plankton and confined to the single vertical tow from 1000 meters at station 64 in the southeastern Pacific, from which 3 females were obtained. The fifth legs of the female are four-segmented, the basal segment with a tuft of long filiform setae, the terminal seg- ment with three plumose setae. Genus MICROCALANUS G. O. Sars, 1901 Microcalanus pusillus G. O. Sars [Microcalanus pusillus G. O. Sars, Crustacea of Norway, vol. 4, p. 156, suppl. pl. 2, pl. 3, fig. 1, 1903.] Abundant in the Sargasso and Caribbean regions and scat- tered in every region of the Pacific, with five or six large COPEPODS OF LAST CRUISE OF CARNEGIE gaps in the distribution. It was taken in 11 nocturnal and ro diurnal surface tows, 39 50-meter tows, and 42 100-meter tows. It migrates to the surface in the night and apparently does not return immediately on the approach of daylight, but is negative to strong light. Microcalanus pygmaeus (G. O. Sars) (Figure 55) [Pseudocalanus pygmaeus G. O. Sars, Norwegian North Polar Exped., 1893-1896, Sci. res., vol. 5, Crustacea, p. 73, pl. 21, 1900. | Found at only two stations in the tropical Atlantic, but more abundant than pusillus in the Pacific. It was present in 12 nocturnal and 21 diurnal surface tows, 60 50-meter tows, and 57 roo-meter tows. Like the previous species, it migrates to the surface in the night and lingers there in the morning, but is negative to strong light. Genus MICROSETELLA Brady and Robertson, 1873 Microsetella norvegica (Boeck) [Setella norvegica Boeck, Forhandl. Vidensk. Selsk. Christiania, p. 281, 1865.] Found at nearly every locality in the Atlantic, but very scattering in the Pacific. It was present in 7 nocturnal and 28 diurnal surface tows, 41 50-meter tows, and 32 1o00-meter tows. The minute size, the laterally compressed body, and the short caudal setae are distinguishing characters. Microsetella rosea (Dana) [Canthocamptus roseus Dana, U. S. Exploring Exped., 1838- 1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1189, 1853; pl. 83, fig. 10, 1855.] Very scattering in the Atlantic but abundant and widely distributed in the Pacific. It was taken in 12 nocturnal and 43 diurnal surface tows, 83 50-meter tows, and 86 100-meter tows. It is probably negative to strong light and migrates to the surface during the night. It is about twice the size of norvegica and usually rosy in color, with caudal setae much longer than the body. Genus MIRACIA Dana, 1846 Miracia efferata Dana [Miracia efferata Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 46, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1260, 1853; pl. 88, fig. 11, 1855.] This species was widely scattered in both oceans, but the localities were long distances apart, and the abundance records were nearly all numerals. It was present in 2 noc- turnal and 19 diurnal surface tows, 19 50-meter tows, and 19 1oo-meter tows. Such a uniform vertical distribution strongly suggests that the species is indifferent to light. Very often the bodies of the specimens preserved in formalin still showed their original red and blue colors. DISCUSSION OF SPECIES Genus MONSTRILLA Dana, 1849 Monstrilla inserta A. Scott [Monstrilla inserta A. Scott, Copepoda of the Siboga Exped., vol. 294, pt. I, p. 237, pl. 57, figs. 7, 8, 1909.] This species was not present in the Atlantic plankton and was taken at two stations (109 and 112) only in the Pacific, in the 50-meter tows. The short first antennae and the struc- ture of the fifth legs are distinctive characters. All the S:boga specimens were taken at the surface, once at night and twice in the daytime, but the Carnegie specimens had migrated downward to the 50-meter level. Genus NEOCALANUS G. O. Sars, 1925 Neocalanus gracilis (Dana) (Figure 84) [Calanus gracilis Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 18, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1078, 1853; pl. 74, fig. 10, 1855. Found at four Atlantic stations and well distributed throughout the entire Pacific. It was taken in 17 nocturnal and 18 diurnal surface tows, 72 50-meter tows, and 78 r100- meter tows, as well as at station 64 in the vertical tow from 1000 meters. It therefore migrates to the surface at night and is probably negative to strong light. The exceptionally long antennae and the peculiarly barbed terminal spine on the exopod of the first legs identify the species. Sars (1925, p. 7) reported this species from 112 stations of the various Monaco expeditions, the majority of the species from depths greater than 100 meters. Neocalanus robustior (Giesbrecht) [Calanus robustior Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 332, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 91, 129, pl. 7, figs. 19, 25, 303 pl. 8, fig. 34, 1892.] Not present in the Atlantic plankton, but well distributed in the Pacific. It was found in 13 nocturnal and 1 diurnal surface tow, 49 50-meter tows, and 51 100-meter tows, and in the vertical tow from 1000 meters, station 64. It is more negative to light than the preceding species, and migrates to the surface at night. The shorter and stouter first antennae and the left fifth foot of the male characterize the species. This species was reported by Sars (1925, p. 8) from only ten of the Monaco stations, and is evidently not so widely distributed as gracilis. Neocalanus tenuicornis (Dana) [Calanus tenuicornis Dana, Proc. Amer. Acad, Arts and Sci., vol. 2, p. 15, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1069, 1853; pl. 73, fig. 10a, b, 1855. Found at four Atlantic stations and sparingly distributed in the Pacific except in the southeastern part. It was present in 8 nocturnal and 4 diurnal surface tows, 32 50-meter tows, and 52 1oo-meter tows. The exceptionally long and filiform 195 first antennae serve to distinguish the species, which 1s less widely distributed than robustior. Genus NESIPPUS Heller, 1865 Nesippus species (Figure 31) One male Nes:ppus was taken at the surface in the western Pacific, station 106, the only record for the cruise. It re- sembled Dana’s Specilligus curticaudis (1849, p. 58; 1853, p. 1375, pl. 95, fig. 6a-A), but differed in many particulars, especially the frontal plates, the anterior and posterior mar- gins of the carapace, and the abdomen. It was impossible to decide from the single specimen whether it was to be re- garded as a variety or a separate species. A drawing is here included for comparison with other species of the genus and as an aid in future identification (fig. 31). Genus OITHONA Baird, 1843 This genus of cyclopoid copepod is characterized by the small size of the species and by the slender and elongated urosome. The present records show that all the species fre- quent the two deeper tows in preference to the surface. In geographical distribution, however, the genus as a whole shows but little partiality for any region or zone, since most stations in both oceans yielded from one to five species. The average number of species for each station for the entire cruise was three, but the number was somewhat larger in the southeastern and central Pacific and considerably smaller in the northern regions of both oceans. S DEPTH IN METERS wH is} DEPTH IN METERS Cuart 12. Daytime vertical distribution of species of Orthona: (1) attenuata, (2) brevicornis, (3) fallax, (4) hebes, (5) linearis, (6) plumifera, (7) robusta, (8) setiger, (9) similis, (10) spini- rostris, (11) vivida. Three species appeared only in the 100-meter tow; one was found at the surface and in the roo-meter tow, but not in the 50-meter tow; one was confined to the two deeper tows. The other six species were present at all three depths and were least abundant at the surface. Three of them were most abundant in the 50-meter tow and the other three in the 1oo-meter tow. The two species s:milis and spinirostris were by far the most numerous, and the former was the one that appeared most often in the nocturnal surface tows. 190 Oithona attenuata Farran [Oithona attenuata Farran, Proc. Zool. Soc. London, 1913, p. 187, pl. 30, figs. 3-7, 1913.] Not found in the Atlantic plankton, but well scattered in the Pacific with numerous large gaps in distribution. It was present in 4 nocturnal and 15 diurnal surface tows, 53 50- meter tows, and 46 100-meter tows. It is thus negative to light, but stops at a depth of 50 meters more often, and with larger abundance records, than at 100 meters. This would be a good species to test for vertical distribution at intervals of ro meters, and would probably yield interesting data, espe- cially between the surface and the 50-meter level. Oithona brevicornis Giesbrecht [Oithona brevicornis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 475, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 538, 549, pl. 34, figs. 6, 7, 1892.| Not found in the Atlantic plankton, and virtually confined to the southeastern region of the Pacific. It was taken in 3 nocturnal and 3 diurnal surface tows, 6 50-meter tows, and II 100-meter tows. With few exceptions the abundance records were expressed in numerals, indicating that the species is comparatively rare. It is also one of the smallest species, and this, with the short antennae and sharply curved rostrum, will serve to distinguish it. It has been reported by Sewell (1924, p. 792) from the brackish water of Chilka Lake in British India. Oithona fallax Farran [O:thona fallax Farran, Proc. Zool. Soc. London, 1913, p. 185, pl. 27, figs. 9-12; pl. 28, figs. 1-3, 1913.] Not found in the Atlantic plankton and confined to six stations in the Pacific, four in the southeastern region at Merriam Ridge (stations 65 to 68) and two in the central part north of Samoa. It was present in 3 surface tows and 5 100-meter tows, but did not appear in any 50-meter tow. It was originally described by Farran (1913, p. 185) from specimens taken at Christmas Island in the Indian Ocean, but this is the first record from the Pacific. Oithona hebes Giesbrecht [Oithona hebes Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 475, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 538, 549, pl. 34, figs. 8, 9, 1892.] This species was not present in the Pacific plankton and was found only at station 30 in the Caribbean Sea, in the 100-meter tow. It has very short first antennae and a swollen metasome, giving it much the appearance of Cyclops. It has been reported from the tropical Pacific by Giesbrecht (1892, p- 538), but this is the first record from the tropical Atlantic. Oithona linearis Giesbrecht | Oithona linearis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 475, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 538, 548, pl. 34, figs. 1, 2, 1892.| COPEPODS OF LAST CRUISE OF CARNEGIE Two specimens were found in the 100-meter tow at station 68 in the southeastern Pacific, and this was the only record for the cruise. It was originally reported from the tropical Pacific, the specimens obtained by Giesbrecht and afterward by Wolfenden (1911, p. 363) haying been taken in vertical hauls from depths of 400 to 4000 meters. This fact helps to explain its scarcity in the Carnegie plankton, and it must be regarded as a deep-water form. Oithona plumifera Baird [Oithona plumifera Baird, The Zoologist (Newman), vol. 1, P. 59, 1843.] This species was well distributed in both oceans, but was not present at stations 10 to 18 (Atlantic), 58 to 68 (except 62) and 115 to 137 (Pacific). It was taken in 8 nocturnal and 20 diurnal surface tows, 65 50-meter tows, and 53 100- meter tows. It is probably more or less indifferent to ordinary light, but becomes negative to strong light and shows a preference for the 50-meter tow rather than the 100-meter tow. The characteristic plumes are usually lacking in pre- served material. Oithona robusta Giesbrecht [Oithona robusta Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 476, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 538, 549, pl. 34, figs. 4, 5, 16, 17, 1892. ] A few females of this species were obtained in the 100- meter tow at station 157 in the tropical Pacific, and this was the only record for the cruise. It is the largest and stoutest of the species, and has a long and sharply pointed rostrum, curved over ventrally so that it is visible in dorsal view. It was originally obtained from the tropical Pacific a little farther west than this Carnegie location. Oithona setiger Dana [Oithona setiger Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1101, 1853; pl. 76, fig. 6a-f, 1855.] This species was present at eight Atlantic stations and ten Pacific stations. It was taken in 2 nocturnal and 3 diurnal surface tows, 4 50-meter tows, and 11 100-meter tows. The comparatively few specimens obtained thus showed a prefer- ence for the roo-meter depth when migrating away from the light. The 2 nocturnal surface tows indicate that the species sometimes visits the surface at night. Giesbrecht’s (1891, Pp. 475; 1892, p. 538) records were from the tropical Pacific and included various depths down to rooo meters. Oithona similis Claus [Oithona similis Claus, Die Copepoden-Fauna yon Nizza, p. 14, 1866.] This is the most abundant and most widely distributed species, not only of its own genus but also of all the plankton copepods. It was found at g2 per cent of all localities through- out the cruise, and the number of specimens in many of the DISCUSSION OF SPECIES tows ran into the hundreds. It was taken in 20 nocturnal and 65 diurnal surface tows, 129 50-meter tows, and 120 100-meter tows, as well as in the vertical tow from 1000 meters, station 64. As this record would indicate, it is more or less in- different to light and was often found equally distributed in all three tows at the same time. In view of this Carnegie record, it seems strange that the species did not appear at all in the S:boga plankton. Oithona spinirostris Claus [Oithona spinirostris Claus, Die freilebenden Copepoden, p. 105, pl. 11, 1863.] This species was also well distributed in both oceans, but not so widely or so abundantly as smulis. It was present in 3 nocturnal and 8 diurnal surface tows, 77 50-meter tows, 84 roo-meter tows, and at station 64 in the vertical tow from 1000 meters. This record shows a definite aversion to light, and some preference for the roo-meter tow; the surface records are very small as compared with the two deeper tows. Farran (1908a, p. 500) gave to this species the new name atlantica, but Sars (1913, p. 6) has clearly shown that it is the same as the species designated spinirostris by Claus (1863, p. 105), and the latter name must be retained. Oithona vivida Farran [O:thona vivida Farran, Proc. Zool. Soc. London, 1913, p. 183, pl. 27, figs. 1-8, 1913.] Three females of this species were obtained at station 37 in the eastern tropical Pacific, 1 specimen in the 50-meter tow and 2 in the 10o-meter tow. It was originally obtained by Farran (1913, p. 183) from the vicinity of Christmas Island in the Indian Ocean, and hitherto has not been re- ported in other collections. It is thus a rare species. These 3 specimens showed an aversion to light, whereas those de- scribed by Farran were taken in shallow water near the shore; the depth of the tow was not given. Genus OITHONINA Sars, 1913 Oithonina nana (Giesbrecht) [Oithona nana Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 538, 549, pl. 4, fig. 8; pl. 34, figs. ro, 11, 20, 24; pl. 44, figs. 4, 6, 1892.] This species was widely scattered in both oceans, but with numerous gaps in the distribution. It was taken in 6 noc- turnal and 15 diurnal surface tows, 32 50-meter tows, and 36 100-meter tows. It is thus probably somewhat indifferent to ordinary light, but becomes more or less negative to strong light, and retires from the surface. It is included by many authors in the genus Oithona, but Sars (1913, p. 5) has given good reasons for considering it a separate genus. Genus ONCAEA Philippi, 1843 Like Oithona, this is a genus of cyclopoid copepods, all of whose species are small, but are inclined to corpulence rather 197 than slenderness. The Caribbean region of the Atlantic and the eastern tropical and southeastern temperate regions of the Pacific contained the largest number of species as well as individuals. The Carnegie records show a definite preference for the deeper tows rather than the surface. Stations 35 to 65 yielded from one to ten species apiece, with an average of six, and it is worthy of note that all these stations are in that region of the Pacific where the oceanic currents are most numerous and active. DEPTH IN METERS a is} DEPTH IN METERS Cuart 13. Daytime vertical distribution of species of Oncaea: (1) anglica, (2) conifera, (3) curta, (4) curvata, (5) dentipes, (6) media, (7) mediterranea, (8) minuta, (9) notopa, (10) ornata, (11) similis, (12) subtilis, (13) tenella, (14) venusta. One species was confined to the surface, one to the 100-meter tow, and one to the two deeper tows. Each of the remaining eleven species was least abundant at the surface and more abundant in the two deeper tows. Four of them were most abundant in the roo-meter tow, three were most abundant in the 50-meter tow, and the other four were evenly divided between the two deeper tows. Attempts have been made by various authors, beginning with Johannes Miller, to divide the plankton into horizontal zones according to the depth at which it is found. In any such division the species of this genus would probably be regarded as belonging to the surface zone, since it is doubtful if any of them descend much below the upper roo meters, practically the surface when compared with the depths of the ocean. Yet the majority of the species show within their limited habitat a more or less well de- fined aversion to the actual surface layer and a preference for the two greater depths. [O. ornata was taken only at night.—Ep.| Oncaea anglica Brady [Oncaea anglica Brady, Trans. Nat. Hist. Soc. Northumber- land and Durham, n. s., vol. 1, p. 220, pl. 6, figs. 1-9, 1905.] Not found in the Atlantic plankton, and confined to the first two stations in the tropical Pacific after passing through the Panama Canal. Two females were taken in the 50-meter tow at station 35 and 1 in the roo-meter tow at station 36. These 3 specimens were evidently negative to light, but the number is too small to warrant a general statement. The species was originally obtained from the North Atlantic, and this is the first record from the Pacific. 198 Oncaea conifera Giesbrecht [Oncaea conifera Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 477, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 603, pl. 2, fig. 10; pl. 47, figs. 4, 16, 21, 23, 28, 34-38, 42, 55, 56, 1892.] This species was found at three stations in the Caribbean Sea and was well scattered in the Pacific, especially in the southeastern region. It was taken in 1 nocturnal and 4 di- urnal surface tows, 10 50-meter tows, and 15 100-meter tows, and in the vertical tow from 1000 meters at station 64. More than half the abundance records were numerals, indicating that the species is nowhere plentiful. It is, however, rather widely distributed, and has been reported from nearly every ocean, including the Arctic and Antarctic. Farran in his account of the Copepoda of the Terra Nova expedition (1929, p. 285) recorded it as “taken three times in hauls beneath the ice.” Oncaea curta G. O. Sars [Oncaea curta G. O. Sars, Bull. Inst. océanogr. Monaco, no. 323, p- II, pl. 4, 1916.] Found between stations 1 and 2 and at three stations in the central tropical Atlantic, and in every region of the Pacific, but in small numbers and with numerous gaps in its distribution. It was taken in 13 nocturnal and 19 diurnal surface tows, 24 50-meter tows, and 24 100-meter tows, and in the vertical tow from rooo meters, station 64. This record suggests considerable indifference to light with a. slight preference for the two deeper tows. As far as is known, this is the first record of the species outside the Mediterranean, where it was originally obtained. The relative size of the genital segment as compared with the rest of the urosome was given by Sars (1916, p. 11) as the most evident char- acter of the species. Oncaea curvata Giesbrecht (Figure 45) [Oncaea curvata Giesbrecht, Rés. voyage S.Y. Belgica, 1897-99, Copepoden, p. 42, pl. 13, figs. 12-17, 1902.] Not present in the Atlantic plankton, and in the Pacific confined to stations 35 to 61, with a single exception. It was taken in 1 nocturnal and 1 diurnal surface tow, 4 50-meter tows, and 4 100-meter tows. In every instance the number of specimens was very small, and the species is evidently rare. Farran in his account of the Copepoda of the Terra Nova expedition (1929, p. 286) stated that this species was “‘fre- quent in the Antarctic, especially under the ice at Winter Quarters.” Oncaea dentipes Giesbrecht (Figure 49) [Oncaea dentipes Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 477, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 603, pl. 47, figs. 7, 17, 41, 51; 52, 1892.] A single female was taken in the 100-meter tow at station 55, and this was the only record for the cruise. It was originally reported by Giesbrecht (1891, p. 477; 1892, p. 591) COPEPODS OF LAST CRUISE OF CARNEGIE from nearly the same locality, and one specimen was ob- tained in the Terra Nova plankton (Farran, 1929, p. 286) off New Zealand in a vertical haul from too meters depth. Oncaea media Giesbrecht [Oncaea media Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol, 7, sem. 1, p. 477, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 602, pl. 2, fig. 12; pl. 47, figs. 1, 11, 29-33, 40, 1892.] Well distributed in both oceans except in the northern regions. It was taken in 24 nocturnal and 36 diurnal surface tows, 39 50-meter tows, and 37 100-meter tows, and in the vertical tow from 1000 meters at station 64. It was repeatedly found in similar abundance in all three tows at the same time, and hence must be regarded as practically indifferent to light. It was found at the surface so often in the daytime that its presence there at night can scarcely be regarded as evidence of migration. Oncaea mediterranea Claus (Figure 44) [Oncaea mediterranea Claus, Die freilebenden Copepoden, p. 159, pl. 30, figs. 1-7, 1863.] Not present in the Atlantic plankton, and in the Pacific found chiefly at stations 54 to 65. It was taken in 14 noc- turnal and 3 diurnal surface tows, 9 50-meter tows, and 12 r00-meter tows, and in the vertical tow from 1000 meters at station 64. It is found almost entirely in the two deeper tows during the daytime, but migrates to the surface at night. It was recorded by Farran (1929, p. 285) as “scarce in the Atlantic but common off New Zealand. Most of the New Zealand specimens retained their orange or golden color after preservation.” This last statement is also true of the Carnegie specimens, many of which were still very brightly colored after four years in formalin. Oncaea minuta Giesbrecht (Figure 47) [Oncaca minuta Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 603, pl. 47, figs. 3, 6, 26, 46, 59, 1892.| This is one of the most widely distributed and abundant species of the genus in both oceans. It was taken in 33 noc- turnal and 63 diurnal surface tows, 106 50-meter tows, and 102 100-meter tows. It was recorded as abundant one hun- dred times and as common one hundred times more. It showed a definite preference for the two deeper tows in the daytime, but migrated regularly to the surface at night. Oncaea notopa (Giesbrecht) (Figure 46) [Oncaea notopus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 477, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 603, pl. 47, figs. 12, 15, 45, 1892. | Found at only four Atlantic stations, but more widely scattered in the Pacific, with numerous and extensive gaps DISCUSSION OF SPECIES in the distribution, one of them including all the stations from 69 to 106 inclusive. It was present in 15 nocturnal and 11 diurnal surface tows, 16 50-meter tows, and 19 100-meter tows, and in the vertical tow from 1000 meters at station 64. The preference for the two deeper tows in the daytime was only slight, and the species would seem to be somewhat in- different to light. The species was reported by Giesbrecht (1891, p. 477; 1892, p. 591) from the tropical Pacific down to 1000 meters, and by Sars (1900, p. 107) from the Arctic Ocean north of the New Siberian Islands. Oncaea ornata Giesbrecht (Figure 48) [Oncaea ornata Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 477, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 604, pl. 44, figs. 50, 51; pl. 47, figs. 20, 24, 49, 53, 1892.] Five females were obtained in a surface tow off Samoa Island at night, and this was the only record for the cruise. The species was originally reported by Giesbrecht (1891, P- 477; 1892, p. 591) from the eastern tropical Pacific, and has not been noted in the plankton of any expedition since then. It is thus very rare, and is probably much restricted in distribution. Oncaea similis G. O. Sars [Oncaea similis G. O. Sars, Crustacea of Norway, vol. 6, p. 193, pl. 109, fig. 1, 1918.] Found at three localities in the Atlantic and well distrib- uted in the southeastern and eastern Pacific, but extremely scattering elsewhere. It was present in 16 nocturnal and 9 diurnal surface tows, 30 50-meter tows, and 24 100-meter tows, and in the vertical tow from 1000 meters, station 64. It thus showed a definite choice of the deeper tows in the day- time and a habitual resort to the surface at night. This is the first record of this species from the Pacific Ocean. Oncaea subtilis Giesbrecht [Oncaea subtilis Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 591, 603, pl. 47, figs. 14, 18, 25, 43, 60, 1892. | Found at only two of the Caribbean Sea stations and almost entirely at the eastern tropical stations in the Pacific. It was taken in 4 nocturnal and 4 diurnal surface tows, 8 50-meter tows, and 6 100-meter tows. Not enough specimens were obtained to warrant any general conclusions, but it seems fairly evenly distributed among the three depths and hence might be considered as probably indifferent to light. Oncaea tenella G. O. Sars [Oncaea tenella G. O. Sars, Bull. Inst. océanogr. Monaco, no. 323, p. 12, pl. 5, 1916.] Found at two Caribbean and three mid-tropical Atlantic stations, but chiefly in the southeastern Pacific. It was present in 12 nocturnal and g diurnal surface tows, 14 50- meter tows, and 18 roo-meter tows, and in the vertical tow from 1000 meters at station 64. It showed, therefore, a 199) moderate preference for the deeper tows by day and migra- tion to the surface at night. This is another of Sars’ (1916, p- 12) species, and was originally obtained from the Mediter- ranean. Oncaea venusta Philippi [Oncaea venusta Philippi, Arch. f. Naturgesch. (Wiegmann), vol. 1, Jahrg. 9, p. 63, fig. 3, 1843.] This shares with minuta the widest distribution and the greatest abundance of any species of the genus. Indeed, they are surpassed in these respects only by Osthona similis among all the copepods of the Carnegie plankton. This species was captured in 31 nocturnal’ and 80 diurnal surface tows, 103 50-meter tows, and 102 100-meter tows, and in the vertical tow from 1000 meters at station 64. It was recorded one hun- dred and fifty-four times as abundant and one hundred times as common. It was found more often than any other copepod distributed equally at all three depths at the same time. It is therefore indiflerent to light, and its vertical dis- tribution is exceptionally uniform. Genus ONCHOCALANUS G. O. Sars, 1905 Onchocalanus cristatus (Wolfenden) (Figure 90) [Xanthocalanus cristatus Wolfenden, Jour. Marine Biol. Assoc., n. s., vol. 7, no. 1, p. 119, pl. 9, figs. 18, 19, 1904.] A single female was taken in the vertical tow from a depth of 1000 meters at station 64 in the southeastern Pacific, and this was the only record for the entire cruise. This species occurred twice in the S/boga plankton in vertical hauls from depths of 1000 and 1536 meters respectively. It is probably, therefore, a deep-water species which stays below the 100- meter level at least in the daytime. Onchocalanus nudipes, new species (Figures 71-83) Occurrence. About 40 specimens in various stages of de- velopment were taken in the eastern, central, and western parts of the tropical Pacific, but none were found in the Atlantic plankton. They were captured in 6 surface tows, 2 50-meter tows, and 3 100-meter tows. No adult males were obtained, although some of the younger stages were prob- ably undeveloped males. Description of female. Body pyriform, the metasome con- siderably widened and much inflated dorsally and ventrally, the urosome one-fourth as long and one-fifth as wide as the metasome and four-segmented. The head is separated from the first segment, and the fourth from the fifth segment. The genital segment is half the length of the urosome and a little wider than the abdomen. The three abdominal segments are equal in length and width, but the anal segment is shortened at the sides. The caudal rami are as wide as long, divergent, and each is armed with four setae of about equal length. The first antennae are slender and twenty-four-segmented, and reach the middle of the urosome. The exopod of the second antenna is twice as long as the endopod and six- segmented, the second segment twice as long as the first. 200 The second maxillae are stout and the last lobe of the basilar part terminates in a very long and strong claw, curved back- ward and ending in a sharp point. At the base of the claw on the inside are two or three long setae. The terminal part is folded against the base of the claw and is armed with five or six sensory appendages and two long setae. The maxilli- peds are long and slender; the proximal segment of the basal part is somewhat swollen, with small setae on the inner margin; the distal segment is narrower and a little longer, with three setae nearer the basal end. The terminal part is made up of five segments, the second one the longest, the terminal one very minute. The exopods of the swimming legs are all three-segmented; the endopods of the first four pairs have one, two, three, and three segments respectively. The first legs have no spines on the posterior surface; the terminal segment of the second endopod has a proximal group of three and a distal group of four spines in an oblique row. The second segment of the third endopod has six spines and the end segment has five; the second segment of the third exopod carries a transverse row of very slender spines close to the base of the segment; the second segment of the fourth endopod has two groups of three spines each in a longitudinal row, and the third segment has a transverse row of three spines near the distal end. The fifth legs are uniramose, three-segmented, and en- tirely destitute of hairs, whence the specific name. The ter- minal segment is conical, with three minute spines at the tip and one on the outer margin near the center. Total length, 2.25 mm; length of metasome, 1.95 mm; width, 1.15 mm. Type. U.S. Nat. Mus. no. 64004. Remarks. This is much the smallest species of the genus, and looks more like Pachos than like any other Onchocalanus species. The strong claw on the second maxillae, the bifurcate rostrum, and the spines on the posterior surfaces of the swimming legs necessitate the reference of the species to the present genus. The species can be identified by the small size, the pyriform shape, and the entire lack of hairs on the fifth legs. Onchocalanus trigoniceps G. O. Sars (Figure 96) [Onchocalanus trigoniceps G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 20, 1905. | A single female of this species was taken in the vertical tow from a depth of 1000 meters at station 64 in the south- eastern Pacific. This is larger than cristatus, but lacks the frontal crest, and is another deep-water species that stays below the roo-meter level in the daytime. It has been re- ported before from the Atlantic, the Mediterranean, and the Antarctic oceans, but not from the Pacific. Genus PACHOS Stebbing, 1910 Pachos punctatum (Claus) [Pachysoma punctata Claus, Die freilebenden Copepoden, p. 163, pl. 25, 1863.| This species was found in a surface tow between stations 1 and 2, near the Sargasso region, and at nine widely sepa- COPEPODS OF LAST CRUISE OF CARNEGIE rated stations in the Pacific, no two of them being consecu- tive or even close together. It was taken in 2 surface tows, 3 50-meter tows, and 5 100-meter tows, all the abundance records being expressed in numerals. The inference from these meager statistics would be that it is nowhere abundant and that it prefers the deeper levels during the daytime. It was originally reported by Claus (1863, p. 163) from Messina in the Mediterranean, and afterward by Brady (1883, p. 121) in the Challenger plankton from the Philippine Islands, and by A. Scott (1909, p. 262) in the Siboga plankton from the western tropical Pacific. As far as is known, the present is the first record from the northern Atlantic. Pachos tuberosum (Giesbrecht) [Pachysoma tuberosum Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 478, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 612, 615, pl. 48, fig. 37, 1892. | This species was not found in the Atlantic plankton, but appeared at four scattered stations in the tropical Pacific. It was not present in any surface tow, but was taken in 2 50- meter tows and 4 1oo-meter tows. These records are even more scanty than those for the preceding species, but, as far as they go, indicate that the species remains at the lower levels during the daytime. It has been reported by Giesbrecht (1891, p. 478; 1892, p. 612) from the Gulf of Panama and by Cleve (1904, p. 194) from the South Atlantic. Genus PACHYPTILUS G. O. Sars, 1920 Pachyptilus abbreviatus (G. O. Sars) [Pontoptilus abbreviatus G. O. Sars, Bull. Mus. océanogr. Monaco, no, 40, p. 19, 1905.] The Carnegie plankton has yielded the first Pacific records for this species, a juvenile male captured in the 50-meter tow at station 39 and a single female from 100 meters at station 113. This species is considerably larger than either species of Pachos. It lacks the small frontal projection, and the erido- pod of the fifth legs is one-segmented. Hitherto, Pachyptilus abbreviatus has been reported only from the temperate Atlantic by Sars (1925, p. 319) and Rose (1929, p. 36), the latter stating that all the species of this genus live at great depths in the ocean. Genus PANDARUS Leach, 1816 Pandarus satyrus Dana [Pandarus satyrus Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 59, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1367, 1853; pl. 95, fig. ta-c, 1855.] Fifteen specimens were taken from the fins and skin of a large shark captured at station 110. This species, named zygaenae by Brady (1883, p. 134), is usually found on sharks of the genus Zygaena. The present host was not recorded, but may well have belonged to that genus. Dana’s (1849, p. 59) original specimens came from the central tropical putirateteeatiennn DISCUSSION OF SPECIES Pacific off Tongatabu Island; the present specimens were captured farther west and north, near the Fleming Deep. Pandarus sinuatus Say [Pandarus sinuatus Say, Jour. Acad. Nat. Sci. Phila., vol. 1, p- 436, 1818.] A single female was captured in one of the nocturnal sur- face tows taken between stations 35 and 36 in the eastern tropical Pacific. It was about two-thirds grown and had not yet fastened upon a host, but remained swimming freely with the other plankton copepods. This species is very com- mon along the Atlantic coast of North America, but this is the first record from the Pacific. Genus PARACALANUS Boeck, 1865 Paracalanus aculeatus Giesbrecht (Figure 101) [Paracalanus aculeatus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 332, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 164, 170,.pl. 9, figs. 20, 26, 30, 1892. ] Not found in the Atlantic plankton, and in the Pacific confined to the southeastern and central parts. It was taken in 3 nocturnal and 5 diurnal surface tows, 14 50-meter tows, and 11 roo-meter tows. It sometimes remains at the surface, but is more often found in the two deeper tows. The radi- ating setae on the caudal rami are often red in the male. Farran (1929, p. 222) has recorded the species as “frequent in the tropical Atlantic and very abundant at some stations.” Paracalanus parvus (Claus) [Calanus parvus Claus, Die freilebenden Copepoden, p. 173, pl. 26, figs. ro-14, 1863.] This small species was very well distributed in both oceans, and approached close to O:thona and Oncaea in abundance. It was taken in 41 nocturnal and roi diurnal surface tows, 128 50-meter tows, and 118 100-meter tows. Such vertical distribution indicates that the species is prac- tically indifferent to light, and this conclusion is supported by the fact that it is repeatedly found in equal numbers in each of the three tows at the same time. Paracalanus pygmaeus (Claus) [Calanus pygmaeus Claus, Die freilebenden Copepoden, p. 174, 1863. | Not found in the Atlantic plankton, but widely scattered in the Pacific with numerous long gaps in distribution. It was taken in 10 nocturnal and 11 diurnal surface tows, 26 50-meter tows, and 30 100-meter tows. These records, like those of aculeatus, suggest a species negative to strong light, which comes to the surface at night and stays there in the morning until the light becomes too strong, when it drops to the 50-meter and 100-meter depths. It has been reported from the North and South Atlantic and the Mediterranean, but this is the first record from the Pacific. Genus PAREUCHAETA A. Scott, 1909 Pareuchaeta grandiremis (Giesbrecht) [Euchaeta grandiremis Giesbrecht, Atti R. Accad. Lincei, Rome, ser: 4, vol. 4, sem. 2, p. 337, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 246, 264, pl. 16, figs. rr, 42; pl. 37, fig. 41, 1892.] A few specimens of this species were found in the 100- meter tow at station 24 in the tropical Atlantic, and this was the only record for the cruise. This species was originally obtained by Giesbrecht (1892, p. 246) from the eastern Pacific near the equator from a depth of 1000 meters, and this Carnegie record is the first from the tropical Atlantic. Pareuchaeta incisa (G. O. Sars) [Euchaeta incisa G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 17, 1905.] Four females of this species were captured in the vertical tow from a depth of tooo meters at station 64 in the south- eastern Pacific. The species was obtained by Sars (1925, p. 117) from considerable depths in the temperate Atlantic and is probably a deep-water form which does not come above the 1oo-meter line in the daytime. It has not been recorded except by Sars, and all his specimens came from the temperate Atlantic. Pareuchaeta tonsa (Giesbrecht) [Euchaeta tonsa Giesbrecht, Bull. Mus. Comp. Zoél., Harvard Coll., vol. 25, no. 12, Copepoda, p. 251, pl. 4, figs. 9, 10, 1895. | This species appeared but four times in the Carnegie plankton hauls: twice in the Atlantic at the 50-meter level, at station 11 where it was abundant and at station 12 where a few were found, and twice in the Pacific, where it proved to be very scarce at the levels fished, for here only 3 females were captured, 2 in the roo-meter tow at station 147, and 1 in the 50-meter tow at station 141. This is apparently a deep- water form that occasionally gets above the 100-meter line. It may be recognized by the sharp points on either side of the last thoracic segment and by the form of the ventral projection of the genital segment. Sars (1925, p. 122) has recorded thirty-six localities for this species, two of them surface tows, the others vertical hauls from depths of 1000 to 5700 meters. Pareuchaeta tumidula (G. O. Sars) [Euchaeta tumidula G. O. Sars, Bull. Mus. océanogr. Monaco, no. 26, p. 15, 1905.] A single female was taken in the 50-meter tow at station 4o in the eastern tropical region of the Pacific. This station was almost on the equator and close to the coast of Ecuador. This is the smallest species of the genus, and has not before been reported from the Pacific. Sars’ (1925, p. 119) speci- mens all came from the temperate Atlantic in vertical hauls from 1000 to 3000 meters. Genus PENNELLA Oken, 1816 Pennella species A free-swimming copepodid larva of some Pennella species was taken in the 100-meter tow at station 155.. This was very similar to the description and figures of the copepodid larva of Pennella varians given by Wierzejski (1877, p. 572). But so little is known of the development of this genus that specific identification is impossible. Genus PHAENNA Claus, 1863 Phaenna spinifera Claus [Phaenna spinifera Claus, Die freilebenden Copepoden, p. 189, pl. 31, figs. 1-7, 1863.] This species was well scattered in both oceans, with numerous large gaps in distribution. It was taken in 7 sur- face tows, 22 50-meter tows, and 23 100-meter tows, and in the vertical tow from 1000 meters, station 64. It is thus negative to strong light, and did not appear in any of the nocturnal surface tows. It is easily recognized in side view by the highly vaulted cephalothorax and the absence of fifth legs in the female. Genus PHYLLOPUS Brady, 1883 Phyllopus helgae Farran (Figure 89) [Phyllopus helgae Farran, Fisheries, Ireland, Sci. Invest. for 1906, pt. 2, p. 83, pl. 9, figs. 5, 6, 1908.] Three females were obtained in the vertical tow from a depth of 1000 meters at station 64 in the southeastern Pacific. This is a deep-water species which has been reported by Sars (1925, p- 342) and A. Scott (1909, p. 148) from moderate depths in the western Pacific. It is possible that deeper tows at other stations in the southeastern Pacific would have re- vealed its presence. The Ssboga plankton contained a single male and female of this species from a depth of 700 meters. Genus PLEUROMAMMA Giesbrecht, 1898 This genus is easily recognized by the circular pigmented light spot on one side or the other of the first thoracic seg- ment. Its species are all negative to light, and not one of them was found at the surface in the daytime. Furthermore, only one of the species was at all well distributed or abun- dant; the other four were much scattered in location and greatly reduced in numbers. Steuer’s (1932; 1933) excellent monograph on this genus shows that each of the species is much more abundant in the Atlantic and Indian oceans than in the Pacific. Pleuromamma abdominalis (Lubbock) [Diaptomus abdominalis Lubbock, Trans. Entomol. Soc. Lon- don, n. s., vol. 4, pt. 1, p. 22, pl. 10, 1856.] Not found in the Atlantic plankton and at only a few localities in the Pacific, long distances apart. It was taken in 2 nocturnal surface tows and 6 roo-meter tows, and in the COPEPODS OF LAST CRUISE OF CARNEGIE vertical tow from 1000 meters, station 64, but not in any 50- meter tow nor at the surface in the daytime. Although it comes to the surface at night, it descends to 100 meters or — more by day and is thus negative to light. Steuer’s (1932, P- 9; 1933, p. 5) distribution map shows this species as very abundant in the North Atlantic in deep water. Pleuromamma gracilis (Claus) [Pleuromma gracilis Claus, Die freilebenden Copepoden, p. 197, pl. 5, 1863.] Found once between stations 13 and 14 in the Atlantic, and widely scattered in the Pacific, with long gaps in distri- bution. It was taken in 12 nocturnal surface tows, 14 50-_ meter tows, and 30 100-meter tows, and in the vertical tow from rooo meters at station 64. It was recorded as abundant — in the single Atlantic surface tow and once in the Pacific at the surface, and as common three times. Therefore, it mi- grates to the surface in considerable numbers at night, although it was not found there at all during the day. eee iene, eee Pleuromamma quadrungulata (F. Dahl) [Pleuromma quadrungulatum F. Dahl, Zool. Anz., vol. 16, no. 415, p. 105, 1893.] A single female of this species was present in the 1o00- meter tow at station 49 in the southeastern Pacific, and this was the only record for the cruise. This species was said by Esterly (1912, p. 315) to be “rather common in all the deeper hauls” off the California coast at San Diego. But he added, “none taken above 170 fathoms.” This suggests that, having been found in the southeastern Pacific, it may be more com- mon there below too meters than would be inferred from this single specimen. Steuer’s (1932, p. 26; 1933, p. 14) distribution map shows this species to be distinctly tropical in habitat. Pleuromamma robusta (F. Dahl) (Figure 98) [Pleuromma robustum F, Dahl, Zool. Anz., p. 105, 1893.] Three specimens of this species were taken in the vertical tow from a depth of tooo meters at station 64, and it was found in the roo-meter tows at six other Pacific stations. A” few individuals also occurred in one 50-meter tow, but none were found at the surface either by day or by night. This species has been reported by Farran (1929, p. 260) as com- mon in a small area south of New Zealand in the Poa Steuer (1932, p. 20; 1933, p. 11) recorded it from the Ant arctic south of Africa, but as much more abundant in the tropical and northern Atlantic. vol. 16, no. 415, Pleuromamma xiphias (Giesbrecht) [Pleuromma xtphias Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 25, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 347, 357, pl. 32, fig. 14; pl. 33, figs: 42, 45, 50, 1892.] Taken in a nocturnal surface tow between stations 20 and 21 in the Atlantic, and in the vertical tow from a depth of DISCUSSION OF SPECIES 1000 meters at station 64 in the southeastern Pacific. It was reported by Farran (1929, p. 260) in a nocturnal surface tow off New Zealand, and hence migrates to the surface at night. In the daytime it probably remains below 100 meters, which accounts for its scarcity in the Carnegie plankton. Steuer (1932, Pp. 5; 1933, p- 3) recorded this species as abundant in the tropical and temperate Atlantic. Genus PONTELLA Dana, 1846 This genus is widely scattered in both oceans, but with a single exception the localities are far apart and the speci- mens are very few. All the species frequent the surface and are rarely found in either of the deeper tows. They are mod- erately large, with a hook on each lateral margin of the head, a single pair of dorsal eye lenses, and a lens at the base of the rostrum for the ventral eye. They are usually found in temperate and tropical regions, but occasionally farther north or south. DEPTH IN METERS Cuart 14. Daytime vertical distribution of species of Pontella: (1) atlantica, (2) cristata, (3) danae, (4) lobiancoi, (5) princeps, (6) securifer, (7) tenuiremis. Four of the species were confined to the surface tows, one appeared both at the surface and in the 100-meter tow, one was confined to the two upper tows, and one was present at all three depths, but these last two were far more abundant at the surface. This, therefore, may fairly be called a surface genus, the stragglers found in the two deeper tows only emphasizing the greater abundance at the surface. Pontella atlantica (H. Milne Edwards) [Pontia atlantica H. Milne Edwards, Hist. nat. Crust., vol. 3, p. 420, pl. 39, 1840.] Found at one station (32) in the Caribbean Sea and at four localities in the Pacific. One of the latter was a noc- turnal surface tow, and all the others were diurnal surface tows. It evidently remains consistently at the surface during the entire 24 hours of the day and takes no part in vertical migrations. Pontella cristata Kramer [Pontella cristata Kramer, Zool. Jahrb., Abth. Syst., vol. 9, p. 721, figs. 1, 4-6, 8, 9, 1896.] Not found in the Atlantic plankton, but present at four localities in the central Pacific, all the specimens coming from surface tows in the daytime. The species was originally obtained by Kramer (1896, p. 720) from a little farther south in the Pacific near New South Wales, Australia. As its specific name suggests, it is distinguished by a low crest on the head. 203 Pontella danae Giesbrecht [Pontella danae Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 28, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 461, 477, pl. 24, fig. 40; pl. 40, figs. 16, 20, 1892.] Not found in the Atlantic plankton, and in the Pacific confined to the southeastern part. It was present in r noc- turnal and 5 diurnal surface tows, and 1 100-meter tow, but not in any 50-meter tow. The urosome is very asymmetrical, the right caudal ramus is exceptionally enlarged, and the lens of the ventral eye at the base of the rostrum is almost spher- ical. This species has not thus far been reported outside the Pacific Ocean. Pontella lobiancoi (Canu) (Figure 94) [Pontellina lobiancoi Canu, Bull. sci. France et Belgique, vol. 19, p- 102, pls. 8, 9, 1888.] Found at three localities in the Atlantic and five in the Pacific. One of the former was a nocturnal surface tow, the others, with one exception, being diurnal surface tows. The exception was a 50-meter tow at station g1, which yielded a larger number of individuals of this species than any other single locality. This would seem to suggest that the species is positive to ordinary light but becomes negative to strong light. Pontella pennata Wilson [Pontella pennata Wilson, Proc. U. S. Nat. Mus., vol. 80, art. 15, p. 27, pl. 1, 19322.] A single female was obtained from the surface tow at station 1 in the Atlantic, and this was the only record for the cruise. Thus far this species has been found only in the North Atlantic not far distant from the American coast. All specimens ever taken were in surface tows, indicating that the species is positive to light. Pontella princeps Dana [Pontella princeps Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 34, 1849; U. S. Exploring Exped., 1835-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1168, 1853; pl. 82, fig. ga-c, 1855. ] Not found in the Atlantic plankton, and in the Pacific confined to eight localities in the southeastern region. It was present in 2 nocturnal and 6 diurnal surface tows and did not appear in either of the two deeper tows. Like atlantica, it apparently remains at the surface both day and night. The left side of the urosome has outgrowths which render it quite asymmetrical. The species has been reported from the Indian Ocean and from the tropical Pacific, but has not been found in the Atlantic. Pontella securifer Brady [Pontella securifer Brady, Voyage of H.M.S. Challenger, Zool., vol, 8, pt. 23, Copepoda, p. 96, pl. 45, 1883.] Found at one station (34) in the Caribbean Sea and at five localities in the Pacific, very widely scattered. All the speci- mens were obtained in surface tows, one of which was noc- 204 turnal, the others diurnal. This, then, is a fifth species which remains at the surface during the day and night and does not descend to lower depths. All the Szboga specimens were taken in surface tows with the exception of 2 specimens which were captured in a vertical haul. Pontella tenuiremis Giesbrecht (Figures 93, 97) [Pontella tentiremis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 28, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 462, 477, pl. 24, figs. 24-26; pl. 4o, figs. 3, 4,7, 37, 1892. Not present in the Atlantic plankton, but well distributed in the southeastern and central Pacific. It was taken in 5 nocturnal and 27 diurnal surface tows, 1 50-meter tow, and I 100-meter tow. It is evidently positive to ordinary light but may become negative to strong light. The genital segment has a flattened genital swelling and a small process on the right side behind it. Genus PONTELLINA (Dana), 1853 Pontellina plumata (Dana) (Figure 100) [Pontella plumata Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 27, 1849.] [Pontellina plumata Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, pp. 1135, 1136, 1853; pl. 79, fig. 1oa-d, 1855.] Well distributed in both oceans, except in the northern regions and in the southern part of the Pacific. It was taken in 8 nocturnal and 33 diurnal surface tows, 37 50-meter tows, and 28 100-meter tows. It is thus almost indifferent to light, but slightly favors the two upper tows. It is very generally distributed in the warm regions of all oceans, but rarely occurs in abundance anywhere. Thirty-four of the present abundance records were solitary specimens and twenty-five others were expressed in numerals. Genus PONTELLOPSIS Brady, 1883 Pontellopsis armata (Giesbrecht) [Monops armatus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 28, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 487, 496, pl. 26, figs. 19, 26, 27; pl. 41, figs. 46, 47, 58, 1892.] Two females of this species were obtained in the surface tow at station 98, and this is the only record for the cruise. This species was reported by A. Scott (1909, p. 170) as “the most abundant member of the genus” in the Szboga plank- ton. It is worthy of note that, with one exception, the Szboga specimens were obtained at the surface. It seems reasonable, therefore, to record the species as positive to light. Pontellopsis lubbockii (Giesbrecht) [Monops lubbocku Giesbrecht, Atti R. Accad, Lincei, Rome, ser. 4, vol. 5, sem. 2, p. 29, 1889; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 487, 496, pl. 26, figs. 18, 32; pl. 41, figs. 60, 63, 68, 1892.] COPEPODS OF LAST CRUISE OF CARNEGIE About a dozen specimens, including 1 male and 2 adult females and the remainder development stages, were taken at the surface at station 40. This is the only record for the cruise, — but the species has been reported before from the tropical Pacific. The long process, enlarged at the tip, at the right posterior corner of the last thoracic segment in the male is a distinguishing character. Pontellopsis perspicax (Dana) (Figure 99) [Pontella perspicax Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 32, 1849.] [Pontellina perspicax Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1155, 1853; pl. 81, fig. 2a-d, 1855.] Not present in the Pacific plankton, but found at six sur-_ face stations in the tropical Atlantic. The structure of the fifth legs in both sexes will serve to distinguish the species. — 4 i (Figures 88, 92) ; [Pontella regalis Dana, Proc. Amer, Acad. Arts and Sci., vol. h 2, p. 31, 1849.] ] [Pontellina regalis Dana, U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1154, 1853; pl. 81, fig. — 1a, b, 1855.] Pontellopsis regalis (Dana) Found at two stations in the tropical Atlantic south of the Sargasso Sea and at four in the eastern tropical Pacific. All” the specimens were taken at the surface. This is the largest species of the genus and may be recognized by the structure — of the fifth legs. Pontellopsis villosa Brady (Figure 91) [Pontellopsis villosa Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 86, pl. 34, figs. 10-13; pl. 35, figs. 14-20, 1883.] surface tow at station 144, in the Pacific north of the Ha waiian Islands, and this was the only record for the cruise. before. Genus PSEUDOCALANUS Boeck, 1872 Pseudocalanus gracilis G, O. Sars [Pseudocalanus gracilis G, O. Sars, Crustacea of Norway, vol. | 4, p. 154, suppl. pl. 1, 1903.] cruise. The number of specimens is far too small to warrant any general conclusions. With (1915, p. 57) considers this species a synonym of P. minutus. DISCUSSION OF SPECIES Pseudocalanus minutus (Krgyer) [Calanus minutus Krgyer, Naturhist. Tidsskr., Kjobenhavn, ser. 2, vol. 2, p. 543, 1848.] This species is easily second in abundance and distribution to Oithona similis. It was found, with few exceptions, at every locality in both oceans. It was taken in 42 nocturnal and 88 diurnal surface tows, 116 50-meter tows, and 106 1oo-meter tows. It was repeatedly found evenly distributed in all three tows at the same time. It would seem, therefore, that it is more or less indifferent to ordinary light but may become somewhat negative to strong light. Genus PPEUDOCHIRELLA G. O. Sars, 1920 Pseudochirella divaricata (G. O. Sars) [Gaidius divaricata G. O. Sars, Bull. Mus. océanogr. Monaco, no, 26, p. 10, 1905.] A single female was taken in the vertical tow from a depth of 1000 meters at station 64 in the southeastern Pacific, and this was the only record for the cruise. Since all the specimens thus far obtained have come from considerable depths, this species might possibly have been obtained in other localities if the tows had descended far enough below the 1oo-meter level. Genus RHINCALANUS Dana, 1853 Rhincalanus cornutus Dana [Rhincalanus cornutus Dana, U. S. Exploring Exped., 1838- 1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1083, 1853; pl. 76, fig. 1a, b, 1855.] This species was well dispersed in both oceans, but with several extensive gaps in its distribution. It was taken in 6 surface tows, 26 50-meter tows, and 23 r1o0-meter tows. It is thus negative to strong light, but it may be more or less in- different to weak light and thus linger at the surface in dull weather. Rhincalanus nasutus Giesbrecht (Figure 114) [Rhincalanus nasutus Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 334, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 152, 160, pl. 3, fig. 6; pl. 9, figs. 6, 14; pl. 12, figs. 9-12, 14, 16, 17; pl. 35, figs. 46, 47, 49, 1892.] This species was a trifle less evenly distributed than the preceding one, and there were even more extensive gaps in the Pacific distribution. It was taken in 6 surface tows, 19 50-meter tows, and 21 100-meter tows. It thus bears the same relation to light as cornutus, from which it can be distin- guished by the fact that the rostral filaments are invisible in dorsal view, whereas they can be seen plainly on either side of the head in cornutus. Genus SAPPHIRINA J. V. Thompson, 1830 This genus includes species which are nearly transparent and strongly depressed, with lamellar caudal rami and a pair 205 of eye lenses on the forehead. They were not found in the northern part of either ocean or at the three southern stations in the Pacific. The majority of them show a preference for the two deeper tows, but one manifests a definite preference for the surface and another is about equally distributed at all three depths. Several were obtained in such small num- bers as to warrant no conclusions. /00 DEPTH IN METERS GH is} 100 DEPTH IN METERS DH Ss Cuart 15. Vertical distribution of certain species of Sapphirina: (1) angusta, (2) auronitens, (3) darwinii, (4) metallina, (5) nigromaculata, (6) opalina, (7) ovatolanceolata, (8) pyrosomatis, (9) salpae. One species was confined to the 50-meter tow and one to the roo-meter tow. Two others were confined to the two upper tows, and the remaining five appeared at all three depths. One of these latter was most abundant at the surface, one in the roo-meter tow, and three in the 50-meter tow. The species of this genus, therefore, differ nearly as much in their vertical distribu- tion as they do in their specific characters. Sapphirina angusta Dana [Sapphirina angusta Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 41, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1240, 1853; pl. 87, fig. 3a, b, 1855.] About equally distributed in both oceans, with several extensive gaps in the Pacific dispersal. It was present in 5 nocturnal and 14 diurnal surface tows, 15 50-meter tows, and 13 roo-meter tows. The daytime distribution was thus prac- tically equal at all three depths, and the species manifested no preference for any one of them. Twenty-one of the records were single specimens, and it is worthy of note that all the nine records of this species in the S:boga plankton were also single specimens. Sapphirina auronitens Claus [Sapphirina auronitens Claus, Die freilebenden Copepoden, p. 153, 1863.] This was the most abundant species of the genus, chiefly in the Pacific plankton. It was taken in 16 nocturnal and 55 diurnal surface tows, 33 50-meter tows, and 29 100-meter tows. The species thus shows a preference for the surface, 206 even without the nocturnal tows, but the attraction cannot be very strong since so many are left in the deeper tows. Sapphirina darwinii Haeckel [Sapphirina darwinit Haeckel, Ztschr. f. Med. u. Naturwiss., Jena, vol. 1, p. 105, pls. 2, 3, 1864.] A few specimens were found in a nocturnal 50-meter tow between stations r and 2 in the Atlantic, and this is the only record for the cruise. In the S7boga plankton this species was captured twice at night, twice in vertical tows from con- siderable depths, and twice at the surface. It is possible that deeper tows might have revealed it at some of the Pacific stations. Sapphirina metallina Dana (Figure 111) [Sapphirina metallina Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 41, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1242, 1853; pl. 87, fig. 5a-c, 1855. ] Not found in the Atlantic plankton, and in the Pacific confined chiefly to the western and central regions. It was taken in 1 surface tow, rr 50-meter tows, and 24 1oo-meter tows. It thus shows definite aversion to light, and in the Siboga plankton was found four times in vertical tows from considerable depths. The two inner terminal setae on each caudal ramus are leaflike, with a wide transparent blade on either side of the central shaft. Sapphirina nigromaculata Claus [Sapphirina nigromaculata Claus, Die freilebenden Copepoden, p. 152, pl. 8, 1863.] Found at eight Atlantic localities, and in the Pacific more numerous in the southeastern and western regions. It was taken in 2 nocturnal and 17 diurnal surface tows, 37 50- meter tows, and 33 roo-meter tows. It is, therefore, negative to light, but comes to the surface at night and is often found there in the daytime. Sapphirina opalina Dana (Figure 112) [Sapphirina opalina Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 45, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1254, 1853; pl. 88, fig. 4a-l, 1855.] Not found in the Atlantic plankton, but present in each of the Pacific regions except the northern, although very widely scattered. It was taken in 2 nocturnal and 3 diurnal surface tows, 13 50-meter tows, and ro roo-meter tows. This species is also negative to light, coming to the surface at night, and being rarely found there in the daytime. Sapphirina ovatolanceolata Dana (Figure 110) [Sapphirina ovatolanceolata Dana, Proc. Amer. Acad, Arts and Sci., vol. 2, p. 44, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1251, 1853; pl. 87, figs. 15a-c, 16a, b, 1855.] COPEPODS OF LAST CRUISE OF CARNEGIE : Not found in the Atlantic plankton, and confined to two localities in the Pacific, one in the eastern and the other in the western tropical region. At the western station it was taken in a daytime surface tow, and at the eastern station in a nocturnal 50-meter tow. The S:boga expedition found this species generally distributed in the Malay Archipelago and elsewhere in the tropical Pacific. Sapphirina pyrosomatis Giesbrecht [Sapphirina pyrosomatis Giesbrecht, Fauna und Flora des Golfes yon Neapel, vol. 19, pp. 619, 641, pl. 52, figs. 12-14, 17; pl. 53, figs. 8, 41, 53; pl. 54, figs. 21, 38, 58, 1892.] Not found in the Atlantic plankton, and confined to three localities in the southeastern Pacific, all three records being single specimens. It was taken at the surface, once in the night and once in the daytime, and once in the 50-meter tow. Apparently this is the first record from the Pacific Ocean, as it has been reported hitherto only from the Atlantic and Mediterranean. Sapphirina salpae Claus (Figure 109) [Sapphirina salpae Claus, Arch. f. Anat., Physiol., wissensch. Med., Jahrg. 1859, p. 270, 1859.] Not found in the Atlantic plankton, but present at four widely separated localities in the Pacific. It was taken once in a nocturnal surface tow and three times in roo-meter tows. Therefore, as far as this meager collection shows, the — species is negative to light and comes to the surface at night. Farran (1929, p. 287) recorded it as “frequent off New Zea- land,” where it was captured at the surface mostly in the night but rarely in the daytime. Sapphirina scarlata Giesbrecht ‘ [Sapphirina scarlata Giesbrecht, Atti R. Accad. Lincei, Rome, : ser. 4, vol. 7, sem. 1, p. 478, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 620, 642, pl. 52, figs. 42, 60, — 61; pl. 53, figs. 12, 39, 62; pl. 54, figs. 25, 31, 72, 1892.] Found at a single station (34) in the Caribbean Sea, and — at four localities in the Pacific. It was taken in 1 diurnal i surface tow, 2 50-meter tows, and 2 roo-meter tows. This meager record suggests aversion to light. This species was — reported by Farran (1929, p. 289) off New Zealand in the Terra Nova expedition, but only a few specimens were taken. Sapphirina stellata Giesbrecht [Sapphirina stellata Giesbrecht, Atti R. Accad. Lincei, Rome, sem. 1, p. 478, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 620, 643, pl. 52, figs. 7-93 pl. 53, figs. 15, 35, 59; pl. 54, figs. 22, 27, 69, 1892.] ser. 4). vols 7 /> Found at three Atlantic and five Pacific localities, the latter all in the western region. It was taken in 1 nocturnal — and 4 diurnal surface tows, 1 50-meter tow, and 3 roo-meteil tows. A. Scott (1909, p. 259) reported this as the most com-_ mon and widely distributed species of the genus in the DISCUSSION OF SPECIES 207 Siboga plankton, and most of the specimens were taken at the surface either at night or in the daytime. Genus SCAPHOCALANUS G. O. Sars, 1900 Scaphocalanus elongatus A. Scott (Figure 113) [Scaphocalanus elongatus A, Scott, Copepoda of Siboga Exped., vol. 294, pt. 1, p. 98, pl. 32, figs. 10-16, 1909.] A single female was obtained in the roo-meter tow at station 107 in the western tropical Pacific, and this was the only record for the cruise. The specimen which A. Scott (1909, p- 98) described under the above name was taken not far from the same locality. Since the Szboga and Carnegie planktons each yielded but a single specimen, the species must be quite rare. Scaphocalanus magnus (T. Scott) [Amallophora magna T. Scott, Trans. Linn. Soc. London, ser. 2, Zool., vol. 6, pt. 1, p. 55, pl. 6, figs. 5-9, 1894.] A single female was obtained in the vertical tow from a depth of rooo meters at station 64 in the southeastern Pacific. It is easily distinguished by the helmet-shaped crest on the forehead and the structure of the fifth legs. Half the speci- mens obtained in the S:4oga plankton were found in vertical tows from considerable depths, and the other half in surface tows at night. It thus seems probable that this is a deep- water species remaining below 100 meters in the daytime. Scaphocalanus medius (G. O. Sars) (Figure 136) [Amallophora media G. O. Sars, Bull. Inst. océanogr. Monaco, no. 101, p. 16, 1907.] A single female was taken in the 1oo-meter tow at station 56 in the southeastern Pacific. This is another deep-water species, and has been found in both oceans, but probably remains below 100 meters most of the time. It has no crest, and the structure of the fifth legs is quite different from that in the other two species of the genus. Genus SCOLECITHRICELLA G. O. Sars, 1902 This genus is distinguished from Scolecithrix by the presence of a fifth pair of legs in the female as well as the male. DEPTH IN METERS Cuart 16. Daytime vertical distribution of certain species of Scolecithricella: (1) abyssalis, (2) auropecten, (3) bradyi, (4) marginata, (5) minor. Scolecithricella abyssalis (Giesbrecht) (Figures 120, 132) [Scolecithrix abyssalis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 338, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 266, 284, pl. 13, figs. 15, 40; pl. 37, fig. 7, 1892.] Not found in the Atlantic plankton, and in the Pacific virtually confined to the eastern and central tropical regions. It was taken in 3 50-meter tows and 7 100-meter tows, but in none of the surface tows either by day or by night. This makes the species negative to light and furnishes no evi- dence with regard to nocturnal migration. As in the Siboga plankton, all the specimens found were females and the male is sull unknown. The species has been reported from the Faroe Channel in the North Atlantic. Scolecithricella auropecten (Giesbrecht) (Figure 121) [Scolecithrix auropecten Giesbrecht, Fauna und Flora des Golfes von Neapel, vol. 19, pp. 266, 284, pl. 13, figs. 8, 18, 22, 27; pl. 37, figs. 3, 10, 1892.] Not found in the Atlantic plankton, and in the Pacific segregated in the southeastern and central regions. It was taken in I 50-meter tow and 5 100-meter tows, and in the vertical tow from 1000 meters, station 64, but did not appear at all at the surface. As in the case of abyssalis, this makes the species negative to light and gives no evidence of noc- turnal migration. The long aesthetasks on the first antennae were very noticeable and looked like strings tied to a wire. The 2 specimens in the S:boga plankton were taken in ver- tical hauls from depths of goo and 1000 meters. Scolecithricella bradyi (Giesbrecht) [Scolecithrix bradyi Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 337, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 266, 283, pl. 4, fig. 7; pl. 13, figs. I, 3, 7, 11, 21, 28; pl. 37, figs. 1, 2, 9, 1892.] Not present in the Atlantic plankton, but well distributed in the Pacific, especially the southeastern and western regions. It was taken in 8 nocturnal and 2 diurnal surface tows, 18 50-meter tows, and 18 roo-meter tows, and at station 64 in the vertical tow from 1000 meters. This record gives good evidence of nocturnal migration to the surface and a return to the deeper layers in the daytime. The fifth legs of the female are so small as to be easily overlooked unless care- fully searched for, but in the male they are fairly large and prehensile. In the Ssboga plankton 5 specimens were taken in vertical hauls from depths of 750 to 1500 meters, and 1 at the surface at night. Scolecithricella marginata (Giesbrecht) (Figures 122, 133) [Scolecithrix marginata Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 338, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 266, 285, pl. 13, figs. 10, 31, 1892.] Not found in the Atlantic plankton, but at a few localities 208 in the eastern Pacific and a few others in the central part north of the Samoan Islands. It was taken in 2 nocturnal and 2 diurnal surface tows, 6 50-meter tows, and 3 100-meter tows. The Carnegie specimens seemed to prefer the 50-meter depth, and this was the only tow in which they were recorded as abundant. Half the S:boga specimens were ob- tained at the surface, some in the daytime and some at night, and the other half were taken in vertical hauls from con- siderable depths. Scolecithricella minor (Brady) (Figures 124, 126, 130) [Scolecithrix minor Brady, Voyage of H.M.S. Challenger, Zool., vol. 8, pt. 23, Copepoda, p. 58, pl. 16, figs. 15, 16, pl. 18, figs. 1-5, 1883.] Found at three stations in the Atlantic and in widely scattered localities in the Pacific. It was taken in 1 surface tow, 8 50-meter tows, and 6 100-meter tows. These few specimens showed a preference for the 50-meter depth and gave no evidence as to nocturnal migration. This species has been reported from the North and South Atlantic and the Indian Ocean, but this is the first record from the Pacific Ocean. Scolecithricella ovata (Farran) (Figure 125) [Scolecithrix ovata Farran, Ann. Rept. Fisheries, Ireland, 1902- 03; pt 2, app. 2, p: 37, pl. 6, fags. 13-18; pl. 7, figs. 1=7, 1905. | ; A few specimens were found in the roo-meter tow at station g in the northern Atlantic, southwest of Iceland, and this was the only record for the cruise. The species was re- ported from the same locality by With (1915, p. 208), and Farran’s (1905, p. 37) original specimens came from the west coast of Ireland. Pearson (1906, p. 18) gave the vertical range as 382 fathoms, which makes it a deep-water species not likely to be obtained in the upper 100 meters. This seems to be a typical Atlantic species and has not as yet been found anywhere else. Scolecithricella porrecta (Giesbrecht) (Figures 127, 134) [Scolecithrix porrecta Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 338, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 266, 285, pl. 13, figs. 6, 41; pl. 37, fig. 11, 1892.] Not found in the Atlantic plankton, and in the Pacific confined chiefly to the region north of 40° north latitude. It was taken in 3 50-meter tows and 5 100-meter tows, but was not found at the surface either by day or by night. The female is distinguished by the exceptionally long spine on the inner margin of the fifth legs. Giesbrecht’s (1888, p. 338; 1892, p. 266) original specimens, on which the species was founded, came from the eastern Pacific just south of the equator, at a depth of 1800 meters, and it has not been re- ported from any other locality. COPEPODS OF LAST CRUISE OF CARNEGIE Scolecithricella spinacantha, new species (Figures 103-108) Occurrence. A few females were found in the 50-meter tows at stations 158 and 159, just north of the Samoan Islands in the tropical Pacific. In company with the adults were some juveniles which had not developed beyond the early copepodid stages, and lacked the fifth legs. Description of female. Metasome elongate-ovate, strongly narrowed anteriorly and more bluntly rounded posteriorly. Head fused with first segment and the two nearly one-half longer than the free thorax and widest across the posterior margin. Fifth segment also fused with fourth, its posterior corners bluntly rounded and projecting slightly backward. Urosome about one-fifth as wide and one-fourth as long as metasome and four-segmented. The genital segment is a little less than half the length of the urosome and slightly wider than the abdomen, with nearly straight sides. The three abdominal segments are about equal in length but diminish in width posteriorly; the anal segment is somewhat triangular, longest on the mid-line and considerably short- ened on the lateral margins, leaving the posterior corners obliquely truncated. The caudal rami are about as wide as long, and divergent, each with four long setae, the second inner one longer than the entire urosome. The rostrum is composed of two short, stout filaments attached to a projection on the forehead, with no cilia visible at their tips. The first antennae are slender and reach to about the middle of the abdomen; the second an- tennae and mouth parts are similar to those of other species of the genus except that the teeth on the chewing blade of the mandibles are longer, more slender, and very unequal in length. They resemble needles or attenuated spines far more than they do ordinary teeth. The first four pairs of swimming legs have three-segmented exopods, and the endopods are one-, two-, three-, and three- segmented respectively. The first and fourth legs have no spines on their posterior surfaces that can be detected, but the second and third legs are covered rather sparsely on the posterior surface with small spines not definitely arranged. The fifth legs are very characteristic and give rise to the specific name; each consists of a single segment and a basal part. The segment is tipped with a short and stout conical spine, inside the base of which at the inner distal corner is another stout spine five or six times as long as the terminal one, with a row of short cilia along its dorsolateral surface. On the outer margin of the segment, just beyond its center, is a large projecting lobe, which, together with the distal outer margin of the segment itself, is fringed with coarse, flattened spines. The distal margin of the lobe, as it curves around to join the side of the segment, forms a sort of sinus which strongly suggests that the segment is really made up of two segments fused. But a careful examination gave no evidence of division on either surface of the leg or in the arrangement of the inner musculature. Total length, 1.05 mm; length of metasome, 0.87 mmj_ width, 0.42 mm. Type. U.S. Nat. Mus. no. 64005. DISCUSSION OF SPECIES Remarks. This is the smallest of the Scolecithricella species here considered, and may be differentiated by its size alone. The fifth legs are very different from those of any species hitherto described and furnish the distinguishing character of the species. From the fact that the development stages, as well as the adults, were at the 50-meter level at both stations, it would seem that the species is probably negative to light. Genus SCOLECITHRIX Brady, 1883 Scolecithrix danae (Lubbock) [Undina danae Lubbock, Trans. Entomol, Soc. London, n. s., vol. 4, p. 21, pl. 9, figs. 6-9, 1856.] This species was very liberally distributed in both oceans except in the northern regions. It was taken in 8 nocturnal and 8 diurnal surface tows, 80 50-meter tows, and 63 100- meter tows, and in the vertical tow from rooo meters, station 64. It thus shows a definite aversion to light and gives good evidence of migration to the surface at night. Genus SPINOCALANUS Giesbrecht, 1888 Spinocalanus abyssalis Giesbrecht [Spinocalanus abyssalis Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 335, 1888; Fauna und Flora des Golfes yon Neapel, vol. 19, p. 209, pl. 13, figs. 42-48; pl. 36, fig. 49, 1892.] Found at three stations in the tropical Atlantic and at many Pacific localities, chiefly in the southeastern region. It was taken in 5 nocturnal and 2 diurnal surface tows, 11 50- meter tows, and 14 r1oo-meter tows. It is thus negative to light and gives proof of migration to the surface at night. Giesbrecht’s original specimens (1888, p. 335) came from the tropical Pacific from depths of 1000 to 4000 meters. Spinocalanus caudatus G. O. Sars [Spinocalanus caudatus G. O. Sars, Bull. Inst. océanogr. Monaco, no. 377, p. 3, 1920.] Not found in the Atlantic plankton, but present in very small numbers in the southeastern and central Pacific. It was taken in r nocturnal and r diurnal surface tow, 3 50-meter tows, and 2 roo-meter tows. These few specimens preferred the two deeper tows, and one of them had come to the surface at night. Spinocalanus magnus Wolfenden [Spinocalanus magnus Wolfenden, Jour. Marine Biol. Assoc., n. s., vol. 7, p. 118, 1904.] Not found in the Atlantic plankton, but captured at five localities in the central Pacific. It was taken in 1 nocturnal surface tow, 2 50-meter tows, and 1 roo-meter tow. The number of specimens in the 100-meter tow was larger than that in the other four combined. Wolfenden’s (1904, p. 118) original specimens came from the North Atlantic, and he afterward found the same species in the Gauss plankton from the Antarctic. 209 Genus TEMORA Baird, 1850 Temora discaudata Giesbrecht (Figures 115, 118) [Temora discaudata Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 5, sem. 1, p. 814, 1889; Fauna und Flora des Golfes yon Neapel, vol. 19, pp. 328, 338, pl. 17, figs. 3, 20, 23; pl. 38, figs. 24, 25, 28, 1892.] Not found in the Atlantic plankton, and in the Pacific confined chiefly to the eastern and southeastern regions. It was taken in 3 nocturnal and 13 diurnal surface tows, 7 50- meter tows, and to roo-meter tows. This distribution in- dicates more or less indifference to light, with a slight preference for the surface. The strongly asymmetrical caudal rami are the chief specific characteristics. Temora longicornis ( Miller) [Cyclops longicornis O. Fr. Miller, Entomostraca, p. 115, pl. 19, figs. 7-9, 1785.] More abundant and more widely distributed in the Atlantic plankton than in the Pacific. It was present in 3 nocturnal and 6 diurnal surface tows, 6 50-meter tows, and 6 1o0o-meter tows. Excluding the night tows, the vertical distribution is exactly even at the three depths, but the abundance records are somewhat larger in the 50-meter tows. The caudal rami are much narrower than in the pre- ceding species, and strictly symmetrical. Temora stylifera (Dana) [Calanus stylifer Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 13, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1058, 1853; pl. 72, fig. 9, 1855.] Segregated in both oceans at certain localities long dis- tances apart, and more abundant than either of the other two species. It was taken in 2 nocturnal and 14 diurnal surface tows, II 50-meter tows, and 8 100-meter tows. It thus shows a slight preference for the surface, but the abundance records at the three depths are practically equal. Genus TEMOROPIA T. Scott, 1894 Temoropia mayumbaensis T’. Scott (Figures 116, 117) [Temoropia mayumbaensis T. Scott, Trans. Linn. Soc. London, ser. 2, Zool., vol. 6, pt. 1, p. 79, pl. 8, figs. 48, 49; pl. 9, figs. 1-12, 1894.] A few specimens, including both sexes, were found in the 1oo-meter tow at stations 35 and 152 in the eastern and central Pacific, respectively. This species was originally described by T. Scott (1894, p. 79) from specimens taken in the Gulf of Guinea, but it has been reported from the Pacific by A. Scott (1909, p. 119) and Farran (1929, p. 257). Nearly all the S:boga specimens were obtained in vertical hauls from considerable depths, which suggests that this is a deep-water species, coming above the soo-meter level only occasionally. Genus UNDEUCHAETA Giesbrecht, 1888 Undeuchaeta major Giesbrecht [Undeuchaeta major Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 335, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 227, 232, pl. 37, figs. 56, 57, 59, 1892.] Not found in the Atlantic plankton, but present at five localities in the Pacific. Three of these were nocturnal sur- face tows, I was at 100 meters, and 1 was in the vertical tow from rooo meters at station 64; the species is thus nega- tive to light but migrates to the surface at night. It was originally obtained from the Pacific and afterward from the North Atlantic, but is not abundant anywhere. Undeuchaeta plumosa (Lubbock) [Undina plumosa Lubbock, Trans. Entomol. Soc. London, n.s., vol. 4, pt. 1, p. 24, 1856.] Not found in the Atlantic plankton, but taken in the Pacific in 2 nocturnal and 2 diurnal surface tows, 3 100- meter tows, and the vertical tow from 1000 meters at station 64. It is known to be a deep-water species, which evidently migrates to the surface at night and sometimes remains there into the forenoon if the light is weak, but usually migrates at least to the 100-meter level in the daytime. Genus UNDINOPSIS G. O. Sars, 1884 Undinopsis bradyi G. O. Sars (Figure 135) [Undinopsis bradyi G. O. Sars, in J. Spaare Schneider, Rept. Invertebrata from the Kvaenangen Fjord, Tromso Mus. Aarsh., no. 7, p. 131, 1884.] A single male was obtained in the 100-meter tow at station 56 in the southeastern Pacific, and this was the only record for the cruise. Only 3 specimens were obtained in the Siboga plankton, and they were captured in two vertical hauls from depths of 750 and 1500 meters. This is probably a deep-water copepod which does not get up to the roo- meter level very often in the daytime. Sars (1902, p. 32) stated that it was always found close to the bottom and that a light dredge must be used to capture it. Genus UNDINULA A. Scott, 1909 Undinula caroli (Giesbrecht) [Calanus caroli Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 4, sem. 2, p. 331, 1888; Fauna und Flora des Golfes von Neapel, vol. 19, pp. 91, 127, pl. 8, fig. 36, 1892.] Not found in the Atlantic plankton, but present in all the regions of the Pacific except the northern. It was taken in 9 nocturnal and 3 diurnal surface tows, 25 50-meter tows, and 1g 100-meter tows. It is thus negative to light and migrates to the surface at night. The males can be distinguished from those of darwinii by the structure of the fifth legs, but the females are so similar to those of darwini that they can be separated from the latter only by the most careful examina- tion. A. Scott (1909, p. 18) is therefore probably right when COPEPODS OF LAST CRUISE OF CARNEGIE he suggests that this difficulty in distinguishing the species is the reason why it has not been recorded in larger numbers. Undinula darwinii (Lubbock) (Figure 119) [Undina darwinit Lubbock, Trans. Linn. Soc. London, vol. 23, p. 179, pl. 29, figs. 4, 5, 1863.] Not found in the Atlantic plankton, but occurred at nearly every locality in the Pacific except in the northern part. It was taken in 28 nocturnal and 14 diurnal surface tows, 71 50-meter tows, and 73 r1oo-meter tows, and in the vertical tow from 1000 meters at station 64. It is thus negative to light and migrates regularly to the surface at night. With most copepod species, when the sexes are unequal in size the smaller sex arranges itself above the larger, but in this species the larger females are found more often and in greater numbers at the surface and in the 50-meter tow, and the smaller males congregate at a lower level. Undinula vulgaris (Dana) [Undina vulgaris Dana, Proc. Amer. Acad. Arts and Sci., vol. 2, p. 22, 1849; U. S. Exploring Exped., 1838-1842 (Wilkes), vol. 14, pt. 2, Crustacea, p. 1092, 1853; pl. 77, fig. 8a-d, 1855.] More widely distributed in the Atlantic than in the Pacific plankon. It was taken in 8 nocturnal surface tows, in which it was more abundant than in any of the diurnal tows. In the daytime it was present in 11 surface tows, 23 50-meter tows, and 16 100-meter tows. Like the preceding species, it is negative to light and migrates to the surface at night. Genus VALDIVIELLA Steuer, 1904 Valdiviella minor Wolfenden [Valdiviella minor Wolfenden, Deut. Siidpolar-Exped., 1901— 1903, vol. 12, Zool., vol. 4, p. 249, pl. 29, figs. 8-11, r9rt.] Not found in the Atlantic plankton, and in the Pacific present in 1 nocturnal surface tow and 1 1oo-meter diurnal tow, and in the vertical tow from rooo meters, station 64. There were 4 specimens in the surface tow and 1 in each of the other tows. This suggests a deep-water species which migrates to the surface at night but goes below the roo-meter level in the daytime. Genus VETTORIA Wilson, 1924 Vettoria granulosa (Giesbrecht) [Corina granulosa Giesbrecht, Atti R. Accad. Lincei, Rome, ser. 4, vol. 7, sem. 1, p. 479, 1891; Fauna und Flora des Golfes von Neapel, vol. 19, p. 645, pl. 49, figs. 39-45; pl. 50, figs. 53, 54, 1892.] Not found in the Atlantic plankton, and in the Pacific confined chiefly to the southeastern and central regions. It was taken in 2 nocturnal surface tows, 3 diurnal 50-meter tows, and 12 diurnal 1oo-meter tows. It migrates at least occasionally to the surface at night, and by day stays in the two deeper tows, preferring the roo-meter level. ii E NATURE Cli ED Barrp, Wititam. 1843. Note on the luminous appearance of the sea with descriptions of some of the entomostra- cous insects by which it is occasioned. The Zoologist (Newman), vol. 1, pp. 55-61. 1850. The natural history of the British Entomos- traca. 8 pts., 364 pp., 36 pls. London. Borcx, AxeL. 1865. Oversigt over de ved Norges kyster iagttagne Copepoder henh¢grende tie Calanidernes, Cyclopidernes og Harpactidernes Famalier. Forhandl. Vidensk. Selsk. Christiania for 1864, pp. 226-281. 1872. Nye Slaegter og Arter af Saltvands-Cope- poder. Forhandl. Vidensk. Selsk. Christiania, vol. 14, Pp- 35-60. Brapy, Grorce S. 1883. Report on the Copepoda collected by H.M.S. Challenger during the years, 1873-76. Chal- lenger Exped., Zool., vol. 8, pt. 23. 142 pp., 55 pls. 1905. On copepods and other Crustacea taken off Northumberland and Durham in July, 1904. Trans. Nat. Hist. Soc. Northumberland and Durham, n. s., vol. 1, pp. 210-223, 4 pls. 1918. Copepoda. Jn: Australasian Antarctic Exped., 1gtiI—14, ser. C, vol. 5, pt. 3. 48 pp., 15 pls. and R. D. Roserrson. 1873. Contributions to the study of the Entomostraca. 8, On marine Copepoda taken in the west of Ireland. Ann. and Mag. Nat. Hist., ser. 4, vol. 12, 1873, pp. 126-142, pls. 8, 9. Canu, Eucrne. 1888. Les Copépods marins du Boulonnais. I: Les Calanidae. Bull. sci. France et Belgique, vol. 19, pp. 78-106, pls. 7-09. Craus, Cart. 1857. Das Genus Cyclops und seine einheim- ischen Arten. Arch. f. Naturgesch. (Berlin), vol. 23 (1), pp- 1-40, pls. 1-3. 1859. Ueber das Auge der Sapphirinen und Pon- tellen. Arch. f. Anat., Physiol., wissensch. Med., Jahrg. 1859, pp. 269-274, pl. 5B. 1863. Die freilebenden Copepoden mit besonderer Berucksichtigung der Fauna Deutschlands, der Nord- see und des Mittelmeeres. 230 pp., 37 pls. Leipzig. 1866, Die Copepoden-Fauna von Nizza. Ein Beitrag zur Charakteristik der Formen und deren Abander- ungen “im Sinne Darwin’s.” 34 pp., pls. 1-4. Marburg and Leipzig. Creve, P. T. 1900a. The plankton of the North Sea, the English Channel and the Skagerak in 1899. Svenska Akad. Handl., vol. 134, no. 2. 77 pp. 19006. The seasonal distribution of Atlantic plank- ton organisms. 368 pp. Goteborg. 1go0-1901. Geographical «distribution of Atlantic Copepoda and their physical condition. Oefy. Vetensk. Akad. Forhandl., Stockholm, vol. 57, no. 2, pp. 139-144. 1904. The plankton of the South African seas. 1, Copepoda. Marine Invest. 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Notice of some genera of Cyclopacea. Amer. Jour. Sci. and Arts, ser. 2, vol. 1, no. 2, pp. 225-230. 1847. Conspectus Crustaceorum quae in orbis ter- rarum circumnavigatione, Carolo Wilkes e classe Rei- publicae Foederatae duce, lexit et descripsit Jacobus D. Dana. Pt. 1. Proc. Amer. Acad. Arts and Sci., vol. 1, pp. 150-154. (Reprinted in [Silliman’s] Amer. Jour. Sci. and Arts, ser. 2, vol. 8, pp. 276-277, 1849.) 1849. Conspectus Crustaceorum quae in orbis ter- rarum circumnavigatione, Carolo Wilkes e classe Ret- publicae Foederatae duce, lexit et descripsit Jacobus D. Dana. Pt. 2. Proc. Amer. Acad. Arts and Sci., vol. 2, pp. 9-61. (Reprinted in [Silliman’s] Amer. Jour. Sct. and Arts, ser. 2, vol. 8, pp. 278-285, 1849.) 1853-1855. United States Exploring Expedition dur- ing the years 1838, 1839, 1840, 1841, 1842, under the command of Charles Wilkes, U.S.N. Vol. 14, pt. 2, Crustacea, pp. 691-1618, 1853; folio atlas, 96 pls., 1855. Philadelphia. Esterty, C. O. 1905. Pelagic Copepoda of the San Diego region. Univ. Calif. Publ., Zool., vol. 2, pp. 113-233, 62 text figs. 1906. Additions to the copepod fauna of the San Diego region. Univ. Calif. Publ., Zool., vol. 3, pp. 53- 2, pls. 9-14. 1gt1. Third report on the Copepoda of the San Diego region. Univ. Calif. Publ., Zool., vol. 6, no. 14, Pp- 313-352, pls. 26-32. 1912. The occurrence and vertical distribution of the Copepoda of the San Diego region, with particular reference to nineteen species. Univ. Calif. Publ., Zool., vol. 9, no. 6, pp. 253-340, 7 text figs. Farran, G. P. 1905. Report on the Copepoda of the At- lantic slope off counties Mayo and Galway. Ann. Rept. Fisheries, Ireland, 1902-03, pt. 2, app. 2, pp. 23-52, pls 3-13. 1g08a. Note on the copepod genus O:thona. Ann. and Mag. Nat. Hist., ser. 8, vol. 2, pp. 498-503. 212 Farran, G. P. 19085. Second report on the Copepoda of the Irish Atlantic slope. Fisheries, Ireland, Sci. Invest. for 1906, pt. 2. 104 pp., 11 pls. rgtr. 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Siidpolar-Exped., vol. 12, Zool., vol. 4, pp. 181-401, pls. 22-44, text figs. 1-82. ] i / LIST OF SPECIES DISCUSSED Species Atlantic Pacific Species Atlantic Pacific AicanbiaiClavisiten ciate cine ho ote cms eit eee x x Clausocalanus arcuicornis............. x x GENIHG. -o.4-4 Golo Ome rctotnings a Orta se x HUCAEUS 42 2-255 tae eee x Tongiremisaercciaestecistsuss ies ce estan x x Glytemnestra rostrata sees x x MOP SENS Mesias seaetels se ewes nat eisuaecve « x Scutellatay? s.)..: sacra ee eee x a NGCrocalanusieibbemaac teers cress octysiee x @onaeateracilise..\..\..chereee eee x GraGilishemuec cite a esee sae vee ee ee x Gopiliaidenticnlatas.- 25s eeee eee x x longicornis x MMA DNS e, fae raysve Roa an Se x THOUACHUISHerspecarctasrstaratiisiss sieve seers x Guiatd rates Fi yeiys oc-crsrse oro 3 NesiSthusespinUlOSUSt esi eee ce san dees x INSCLICVE oo Gan ree eerie toaicroinc-40-0 x PC GiGenS arma uusSri)sjate mires = css-svastsy a ss x x WL EU Cay waite <5 sisi aie cartel omen x Amallophorarty pica sss ese se° x Gonycaensracilishennmjncinee ieee x x /Naveilloilovries irGueiis sn eouceascouuwoapecse x ANONEW Sle ye suarse marsecihs le hens cee ee x OMEUSIRONS. oer seickcsiey- age cur ste sauce ieee x VIL CILLGUS meme aetewreeer crs heen i eae x x DEO PING Udiews ors arts cuisine eins site ween x Catisieryegrsrs ata cias ans aae i ees x VULCAN cisyeecicesusraiesahesas ace s-aeceys tye 61s x Glanisitvwaeriae te ctratinc- ceteamcraee x x Anomalocera patersonil....sco.+.sssess0e- x x GraSsiuSCuULUS een deiner eee x x PAC TEINS ISCLOSUSHecuerriate ence etas ere ete eects x Cia binSiegreye eae eres laleieas sessions bee me x Augaptilus longicaudatus................ 3 HAC CUS Has atesie es hares stresses x x Bathycalanusirigidusae. eacnes- sce eee es - x HUG OL elewen et taractstsrs-s asec cea xs x (Galanopiavamericanal-sty- seein sete ees x PIESHLEGhhippE ere cce heel x GINDUISE 5 6 state oo cote d Gunn cine One aaIoe 3K x IANS. ood oo end SOO Ren eo aicien ee 35 x WalanUsiGniStabuser erates eta eres eens x llittloent Gos coo dee cen one coe rem x x MEIGS sages ace soe co ken cadones x x longisty liste atoctsisrccscc calimee cee x nARO HACKERS... c44 eae 0nraoenoooeeus x x hib Docking cerietccctca. eats x Dy PETMOLCUSH ciara tees t feces ieee x fPLICON a oo coco Ono certs x x THO)? 5/16 Si GIoe ODIO IIo ORR Ole CGO CRE x x ONO: cnpo.s oc oe Cb BRIO GC On Ee x x PRO PING UUS! ars cye eestor sesretesieayerare se cuets x x paciheusmeerrnine «cceccmis seer ce x HOMSIEC bg gto SUG RO Re So aemn anon x PUTTS nyc cise roar as octane x x Galocalanusipavoracaeaccraces sass: cee x x RODUSEUS mmerer erat ve cieiene ste ave seals x Dlumulosushepetry-eedrtet. il oars cas x SPECIOSUS He eyseyscese aysis oie)s ove suseralacoe x x SEW TE MIS Me reese ve raya ec ctars lola = ral os avers x x EV DIGUS rere nica a iam etic reat x x @andaciavaethiopicaiys.). 24.74. e106 0 oc eras x x Danodes plumata, n. gen. and n. sp....... x EAFIOTEALEE Nera coin 05 is ROT RENE SR RRR SECS x Drepanopus pectinatus..............- x folie tales erin tir sscnsye yaa stasis ce xe Dysramusratilanticus= saseeeieaeeeenes a DispInOsasasteri nineteen aes x x Mnaeeideusibradivitemeceme eerie x Galtilareyn acer goi te aac sale asa ations x SERA; ocoaaweeedereea mane s x GUase veel saees reas s/c llcvoeeogsboee east x Euaugaptilus filigerus..............-.. x FACIE ear mer meres ccs Acisepteusinite cele sree x ucalanustattentiatussesemeneer eae ecee ace x x ARE ono epoance Rat OUnDEEm Some x GLASS S HW ee recto i rs arefticseansie sie a cheushe Het x TOTS a Oto CIMA eae ene Roce x x Clongatliss sce mc sess tence ce eka oe or x x pachiyvdactylaerrnjariccciacaiecrere coe ees x x MONAGHMIS Mere a ere Maier eset 0 STiiTayD) ESR Ae. 8 eteanio to euerCneT Cee ari EEE RR x x POMUCKOMA CUS aiite a ciciciiette isis aetaeene x COMUITMAN Als reyes ciaisichess creme ls eteT is x Sublenise pac cemetery sen kevlar x WWI NCAT ioisre Sirem’s peNatag eee coke eames x uchaetabacutar.