90 CONTRIBUTIONS TO DEVONIAN PALEONTOLOGY. [bull. 244. 
Zone 19 of Hollowing Run section (1^ J.). —The 90 feet of bedsl 
above zone 18 contain few fossils. 
Zone 20 of Hollowing Run section (Ipj^ A). — The species comprising' 
the faunule of this zone are the following: 
Faunule of zone, 20 of Hollowing Run section {1454 A). 
[a, abundant; c, common; r, rare.] 
1. Cystodictya meeki (a). 
2. 8tropheodonta (Leptostrophia) inter 
strialis (r). 
3. A try pa reticularis (c). 
4. Spirifer pennatus var. posterus (a). 
5. Spathella typica (r). 
6. Paheoneilo plana (r). 
7. Macrodon sp. nov. (r). 
8. Pterinea cf. reproba (r.) 
Zone 21 of Hollowing Bun section (14-54- A). — About 100 feet of; 
dark-olive sandstone, having very few fossils, follow the last zone. 
Zone 22 of Hollowing Bun section {ll±51p A). — A 2-inch band, com- 
posed principally of a mass of Cystodictya, affords the following species: 
Faunule of zone 22 of Hollowing Run section (1454 A). 
[a, abundant; r, rare.] 
1. Cystodictya meeki (a). 
2. Crinoid stems (r). 
3. Productella speciosa (r). 
4. Pugnax pugnus (r). 
5. Cyrtina hamiltonensis (r). 
6. Paheoneilo sp. (r). 
These species are all forms well known in the Ithaca fauna. It is to 
be noted that Pugnax pugnus occurs repeatedly in this section, as it 
does in the Catawissa and Ithaca sections. 
Zone 23 of Hollowing Run section (U+S^ ^4).— Above zone 22 are 651 
feet of sandy beds, holding few fossils. 
Zone 21f, of Hollowing Run section (11^5^ A). — The following species 
are from 5 feet of olive-gray shales: 
Faunule of zone 24 of Hollowing Run sectioyi (1454 A) 
1. Stropheodonta (Leptostrophia) interstrialis, (common). 
2. Schizophoria striatula (abundant) . 
.'!. A try pa reticularis (common). 
Zone 25 of Hollowing Hid, section (11^5^ A). — One hundred and sev- 
enty feet of dark olive sand}^ beds, barren, except for occasional bands 
of crinoid stems or Cystodictya, follow the last zone. 
Zone 26 of Hollowing Run section (11^5 1^ A). — The 10 feet of beds 
comprising this zone afforded only a single species, Schizophorm 
striatula which is rare. 
Zone 27 of Hollowing Run section {llfi^ A). — Sandy beds, 70 feet 
thick and apparently barren, follow the last zone. 
Zone 28 of Hollowing Run section (lJ/,5^ A). — Only two species, Pr<>- 
ductella cf. speciosa and Atrypa cf. reticularis, could be recognized in 
this zone. They are rare. 
