My observations cover a period of two months, from the 1st of July to the 1st of September. During that time I was able to study and describe 72 species representing 55 genera, all from the limited space mentioned above. In addition to these there are a few genera and species upon which I have insufficient notes, and these I shall reserve until opportunity comes to study them further.

I take this opportunity to express my thanks to Dr. Hugh M. Smith for many favors shown me while at Woods Hole.

In dealing with these marine forms from the systematic standpoint, two courses are open to the investigator. He may make numerous new species based upon minor differences in structure, or he may extend previous descriptions until they are elastic enough to cover the variations. The great majority of marine protozoa have been described from European waters, and the descriptions are usually not elastic enough to embrace the forms found at Woods Hole. I have chosen, however, to hold to the conservative plan of systematic work, and to make as few new species as possible, extending the older descriptions to include the new forms.

The different classes of Protozoa, and orders within the classes, are distributed more or less in zones. Thus the Infusoria, including the Ciliata and the [Suctoria], are usually littoral in their habitat, living upon the shore-dwelling, or attached, water plants and upon the animals frequenting them. It is to be expected, therefore, that in forms here considered there should be a preponderance of Infusoria. Flagellated forms are also found in similar localities, but on the Surface of the sea as well; hence the number described in these pages is probably only a small proportion of the total number of Mastigophora in this region. The Sarcodina, including the Foraminifera and the Radiolaria, are typically deep-sea forms and would not be represented by many types in the restricted locality examined at Woods Hole. Two species, Gromia lagenoides and Truncatulina lobatula, alone represent the great order of Foraminifera, while the still larger group of Radiolaria is not represented at all.

The Protozoa described are distributed among the different orders as follows:*

Class SARCODINA.
Subclass Rhizopoda.
Order Amœbida.
1. [Amœba guttula] Duj
2. [Amœba sp.]
3. [Trichosphærium sieboldi] Schn.
Order Reticulariida.
Suborder Imperforina.
4. [Gromia lagenoides] Gruber.
Suborder Perforina.
5. [Truncatulina lobatula] Walker & Jacob.
Subclass Heliozoa.
Order Aphrothoracida.
6. [Actinophrys sol] Ehr.
Order Chlamydophorida.
7. [Heterophrys myriapoda] Archer.
Class Mastigophora.
Subclass [Flagellidia].
Order [Monadida].
8. [Mastigamœba simplex], n. sp.
9. [Codonœca gracilis], n. sp.
10. [Monas sp.]
Order [Choanoflagellida].
11. [Monosiga ovata] S. Kent.
12. [Monosiga fusiformis] S. Kent.
13. [Codonosiga botrytis] (Ehr.) J. Cl.
Order [Heteromastigida].
14. [Bodo globosus] Stein.
15. [Bodo caudatus] (Duj.) Stein.
16. [Oxyrrhis marina] Duj.
Order [Euglenida].
17. [Astasia contorta] Duj.
18. [Anisonema vitrea] Duj.
Order Silicoflagellida.
19. [Distephanus speculum] Stöhr.
Subclass [Dinoflagellidia].
Order Adinida.
20. [Exuviælla lima] Clenk.
21. [Exuviælla marina] Clenk.
Order Diniferida.
22. [Gymnodinium gracile] Bergh.
23. [Glenodinium cinctum] Ehr.
24. [Glenodinium compressa], n. sp.
25. [Peridinium digitale] Pouchet.
26. [Peridinium divergens] Ehr.
27. [Ceratium tripos] Nitsch.
28. [Ceratium fusus] Ehr.
29. [Amphidinium operculatum] Clap. & Lach.
Class Infusoria.
Subclass Ciliata.
Order [Holotrichida].
Family [Enchelinidæ].
30. [Lacrymaria lagenula] Cl. & Lach.
31. [Lacrymaria coronata] Cl. & Lach.
32. [Trachelocerca phœnicopterus] Cohn.
33. [Tiarina fusus] Cl. & Lach.
34. [Mesodinium cinctum], n. sp.
Family [Trachylinidæ].
35. [Lionotus fasciola] Ehr.
36. [Loxophyllum setigerum] Quenn.
Family [Chlamydodontidæ].
37. [Nassula microstoma] Cohn.
38. [Chilodon cucullulus] Müll.
39. [Dysteria lanceolata] Cl. & Lach.
Family [Chiliferidæ].
40. [Frontonia leucas] Ehr.
41. [Colpidium colpoda] Ehr.
42. [Uronema marina] Duj.
Family [Pleuronemidæ].
43. [Pleuronema chrysalis] Ehr.
44. [Pleuronema setigera], n. sp.
45. [Lembus infusionum], n. sp.
46. [Lembus pusillus] Quenn.
Family [Opalinidæ].
47. [Anoplophrya branchiarum] Stein.
Order [Heterotrichida].
Family [Bursaridæ].
48. [Condylostoma patens] Müll.
Family Halteridæ.
49. [Strombidium caudatum] From.
Family [Tintinnidæ].
50. [Tintinnopsis beroidea] Stein.
51. [Tintinnopsis davidoffi] Daday.
Order [Hypotrichida].
Family [Peritromidæ].
52. [Peritromus emmæ] Stein.
Family [Oxytrichidæ].
53. [Epiclintes radiosa] Quenn.
54. [Amphisia kessleri] Wrzes.
Family [Euplotidæ].
55. [Euplotes charon] Ehr.
56. [Euplotes harpa] Stein.
57. [Diophrys appendiculatus] Stein.
58. [Uronychia setigera], n. sp.
59. [Aspidisca hexeris] Quenn.
60. [Aspidisca polystyla] Stein.
Order [Peritrichida].
Family [Lichnophoridæ].
61. [Lichnophora macfarlandi] Stevens.
Family [Vorticellidæ].
62. [Vorticella marina] Greeff.
63. [Vorticella patellina] Müller.
64. [Zoothamnium elegans] D'Udek.
65. [Cothurnia crystallina] Ehr.
66. [Cothurnia nodosa] Cl. & Lach.
67. [Cothurnia imberbis] Ehr.
Subclass [Suctoria].
Family [Podophryidæ].
68. [Podophrya gracilis], n. sp.
69. [Ephelota coronata] Wright.
Family [Acinetidæ].
70. [Acineta divisa] Fraip.
71. [Acineta tuberosa] Ehr.
Family [Dendrosomidæ].
72. [Trichophrya salparum] Entz.
* This classification includes only the orders and families represented at Woods Hole

Genus AMŒBA Auct.

The pseudopodia are lobose, sometimes absent, the body then progressing by a flowing movement; the body consists of ectoplasm and endoplasm, the latter being granular and internal, the former hyaline and external. There is always one nucleus and one vacuole, but both may be more numerous. Reproduction takes place by division or by spore-formation. Fresh-water and marine.


Fig. 1.—
Amœba guttala.
[ ENLARGE ]