The Division of the Psalter into Kathismas

A kathisma (pl. kathismas or kathismata; from Grk. kathemai, "sit") is a twentieth part of the Psalter, that is, a section conveniently readable in one sitting or session. Each of the twenty kathismas is subdivided into 3 sections called stases or antiphons. A kathisma is often followed by meditative expository hymns called sessional hymns (from Latin  sedere , "sit"; Grk.  kathismata , Slav.  sedalny). While it is advantageous to read from the Septuagint version of the Psalter, the Hebrew numbering is provided as well. The service books provide a year-round schedule of Psalter readings at vespers and Psalter readings at matins (orthros).


Greek Numbering  of Psalms


Kathisma

Hebrew Numbering of Psalms

 Stasis 1 Stasis 2
Stasis 3
 Stasis 1
Stasis 2
Stasis 3
1-3
4-6
7-8
I
1-3
4-6
7-8
9-10
11-13
14-16
II
9-11
12-14
15-17
17
18-20
21-23
III
18
19-21
22-24
24-26
27-29
30-31
IV
25-27
28-30
31-32
32-33
34-35
36
V
33-34
35-36
37
37-39
40-42
43-45
VI
38-40
41-43
44-46
46-48
49-50
51-54
VII
47-49
50-51
52-55
55-57
58-60
61-63
VIII
56-58
59-61
62-64
64-66
67
68-69
IX
65-67
68
69-70
70-71
72-73
74-76
X
71-72
73-74
75-77
77
78-80
81-84
XI
78
79-81
82-85
85-87
88
89-90
XII
86-88
89
90-91
91-93
94-96
97-100
XIII
92-94
95-97
98-101
101-102
103
104
XIV
102-103 104
105
105
106
107-108
XV
106
107
108-109
109-111
112-114
115-117
XVI
110-112
113-116:9
116:10-118
118:1-72
118:73-131
118:132-176
XVII
119:1-72 119:73-131 119:132-176
119-123
124-128
129-133
XVIII
120-124
125-129
130-134
134-136
137-139
140-142
XIX
135-137
138-140
141-143
143-144
145-147
148-150
XX
144-145
146-147
148-150