274 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Dentalium, Area, 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, etc. 

 There can be no question as to their age, as they are connected with the 

 Chipola through having in common species found in Jamaica (Bowdeu 

 beds). The 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, Malea (camura 

 Guppy, also St. Domingo and Jamaica), Solarium (quadriseriatum Sby., 

 Haiti), Dentalium (2 sp. also in Gatun beds, Haiti, Jamaica, etc.), 

 Cadulus (sp. also in Haiti), Leda (tedseformis Guppy, two sp., also in 

 Haiti), Area (consobrina Sby., Jamaica, Trinidad), Pecten (like floridus 

 Hds., also Jamaica), Avicula (atlantica Lane, Jamaica and Pliocene and 

 recent), Lucina (small like crenulata), Cardium (haitense Sby., Cura- 

 90a, Jamaica, Haiti), Cardium (large, with many ribs), Venus (mac- 

 tropsis Conr., also at Gatun), Dosinia (cyclica Guppy, Trinidad), 

 Cytherea (dariena Conr. 1 ? 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. 



Costa 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. VIII. 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. 



