METHODS 



The samples were examined in the original sea water 

 and formalin without other treatment than the occasional 

 replacement of loss by evaporation with distilled water. 

 It is thus possible carefully to orient the organism under 

 the cover slip and to secure diverse views of the same 

 individual. There does not seem to he any satisfactory 

 method of sealing off mounts in formalin. A few smears 

 of plankton were made, however, and mounted either in 

 Venice turpentine or in balsam. These were used to 

 supplement the routine examinations. Adequate micro- 

 scopes and maximum equipment were used at all times 

 in the examination of the material. 



After a sufficient knowledge of the species of Tintin- 

 noina had been obtained, each sample was systematically 

 searched by the use of the mechanical stage until all the 

 species had been detected. Each sample, after being 

 thoroughly shaken, was examined on a standard slide 

 under a long cover slip, and several slides were made of 

 it. When the whole sample had been investigated, the 

 material was washed back into the original phial. Care 

 was taken that slides, slips, pipettes, and other instru- 

 ments were cleaned before another sample was opened. 

 The camera lucida was always attached to the microscope 

 so that drawings could be made at once when a desired 

 individual was discovered. In order to have some sem- 

 blance of quantitative record of frequency in individuals 

 of the component species of each net sample, records 

 were made during the search of the sample up to the 

 first hundred individuals examined. Thereafter each 

 additional species was recorded as merely present. The 

 number of individuals recorded is thus the percentage in 

 that sample. These records refer solely to the relative 

 numbers of different species in the one sample, and do 

 not indicate the relative numbers of the same species in 

 other samples. In the examination of the pump samples, 

 the whole number of individuals of all species found was 

 counted out directly, so that in some instances several 

 hundred were recorded. These are reported fully. In 

 most cases the numbers were small and are recorded with 

 those of the net samples without differentiation. 



The manner of collection, and of accumulation of 

 physical data, is recorded in the general survey of the 

 expedition, as is also the list of species by station and 

 depth. 



Drawings with the camera lucida at standard magni- 

 fications were accumulated in great number during the 

 examination of the plankton. Several thousand sketches, 

 with additional notes when necessary, were thus brought 

 together. From these the finished drawings were made 

 up, and the range of variation ascertained. All the 



descriptions of species in this report are the result of the 

 examination and measurement oi these drawings. In ibis 

 way it became possible to describe a large fauna accu- 

 rately and to determine at a later time the exact status oi 

 aberrant individuals. Stress was laid on the finding and 

 recording of these unusual individuals. Most of the fin- 

 ished drawings are selected to show some unusual feature 

 of morphology. Since the majority ol the oceanic spei i< S 

 have been figured previously, it was not considered neces- 

 sary to illustrate all species, especially in those instances 

 in which the material of the Carnegie was not particu- 

 larly different from that already described. The descrip- 

 tions in all instances, however, are of loricae of species 

 found in the collection. Thus these descriptions may 

 differ from those given in earlier papers. 



In this report each character has approximately the 

 same place in the description and so far as possible is 

 discussed in similar phraseology. For the families, sub- 

 families, and genera, synonymy, relationships, and gen- 

 eral distribution are given. The descriptions of the 

 species include synonymy, description of specimens found 

 in the Carnegie material, variations, comparisons, history, 

 and occurrence in the material of the expedition. Because 

 the various genera are distinctly different in form, it is 

 not always possible to apply the same procedure of 

 description to them all, or to use an identical terminology. 

 Adjectives and adverbs used in the descriptions are to be 

 understood in their usual sense, although they are seldom 

 quantitatively exact. 



The families, subfamilies, and genera are arranged in 

 a presumed order of natural relationship, based on the 

 comparative structure of the lorica. The species are 

 arranged within each genus alphabetically. A number of 

 changes in nomenclature and systematic arrangement 

 have been made in an attempt more naturally to separate 

 the families, genera, and species. The relations of the 

 species to one another are treated in the paragraph on 

 comparisons. 



In the synonymy, only those forms recorded since the 

 publication of the Conspectus by Kofoid and Campbell 

 (1929) are given. In that monograph all previous sig- 

 nificant literature is reviewed. 



The records of distribution are arranged according to 

 the natural areas of distribution of Gerhard Schott, which 

 regions are based on the physical conditions of the sea 

 water. The geographical distribution thus does not 

 strictly follow the ocean currents, since these are difficult 

 to limit and are subject to different physical conditions 

 along their lengths. The accompanying table gives a 

 summary of the route of the Carnegie. See also map 1. 



