274 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Dentalium, Arca, Divaricella, Cryptodon, Cardium, Venus or Cytherea 
(small thin form), Callocardia, Corbula (vieta Guppy), Pholadomya? 
(fragment). 
E. Monkey Hill Beds. 
These are of a softer, more evenly grained rock than the Gatun beds, 
and in the greensand grains recall the Mindi Hill, but the species of 
Monkey Hill fossils belong in shallower water, and there are many 
which agree with those found in St. Domingo, Trinidad, Jamaica, ete. 
'There can be no question as to their age, as they are connected with the 
Chipola through having in common species found in Jamaica (Bowden 
beds). Тһе genera observed in the fossil fauna of Monkey Hill are as 
follows: Haminea, Conus (one very large sp.), Conus (catenatus Sby., 
Haiti), Terebra (2 sp., 1 also Chipolan), Pleurotoma (pontonensis Dall, 
St. Domingo), Pleurotoma (like Henikeni Sby., Jamaica), Pleurotoma 
(3 sp., 1 also in Haiti), Astyris, Marginella (2 sp.) Phos (3 sp., all also in 
Haiti) Nassa, Persona, Natica (subg. Cochlis) operculum, Turritella 
(altilira Conr., like Chipolan sp.), Cerithiopsis, Simnia, Malen (camura 
Guppy, also St. Domingo and Jamaica), Solarium (quadriseriatum Sby., 
Haiti), Dentalium (2 sp. also іп Gatun beds, Haiti, Jamaica, ete.), 
Cadulus (sp. also in Haiti), Leda (tedeformis Guppy, two sp., also in 
Haiti), Arca (consobrina Sby., Jamaica, Trinidad), Pecten (like floridus 
Hds., also Jamaica), Avicula (atlantica Lane, Jamaica and Pliocene and 
recent), Lucina (small like erenulata), Cardium (haitense Sby., Cura- 
qoa, Jamaica, Haiti), Cardium (large, with many ribs), Venus (mac- 
tropsis Conr, also at Gatun), Dosinia (cyclica Guppy, Trinidad), 
Cytherea (dariena Conr. ? Haiti), Crassinella (martinicensis Guppy, 
Martinique, Trinidad, Jamaica), Tellina (dariena Conr.), Tellina (sp.), 
Abra, Thracia (like undulata, also Gatun), Corbula (vieta Guppy, Trin- 
idad, etc.), Corbula (cubaniana d'Orb., Jamaica, also Pliocene and 
recent). 
No. 50 is Pleistocene, mixed with recent and older fossil shells. 
Oosta Rica. 
The Pliocene of Limon has been worked upon by Gabb (who died 
before finishing his work, so that the list in Journ. Acad. Nat. Sci. Phila., 
2d ser, Vol. ҮШІ. No. 4, p. 349, does not cover all he collected), and 
No. 67 appears to be part of it. It contains Drillia (perspirata Dall), 
Dolium, Lima (scabra Lam.), and fragments of Vermetus. No. 84 is 
also Pliocene. No. 83 has mixed Pliocene, Oligocene, and recent speci- 
mens. No. 85 appears to be Pleistocene or recent. 
