PANAMIC-PACIFIC PELECYPODA 1? 



polita, rare at most other localities, are common here, as well as a host of 

 smaller forms, all of which must find congenial living quarters in the slimy- 

 mud outside. For the newcomer to Panama and to most of the shelters in 

 residence in the Canal Zone, the favorite localities for collecting are Palo 

 Seco (near the Leper colony) and Venado Beach. Both places are on the 

 west side of the canal; both offer expansive mud flats, sand bars, rocky- 

 areas exposed at low water. Collecting is always best at night with a strong 

 lantern, as many shy mollusks, which in the daytime lie buried in the mud 

 or hidden under rocks, are then active and appear on the surface. A shelling 

 spree in Panama at midnight at the right season and under proper guidance 

 is an unforgettable experience, well worth the tramp through mud, with 

 sore back, and general exhaustion which is sure to follow the next day. 

 Almost any part of the long coastline of Panama offers good collecting of 

 some sort but places as productive as Venado Beach are few. Perhaps the 

 best locality in Panama outside of Venado Beach is Biicaro at the southern 

 end of the Los Santos Peninsula, but at present difficult of access. 



MoUuscan records from western Colombia are scanty as much of its 

 coastline has not been well explored, its northern part from Buenaventura 

 to the Panama border not readily accessible by ordinary means of trans- 

 portation, while its southern half is almost one continuous line of mangrove 

 swamps. Our molluscan records for this coast are confined largely to the 

 general vicinity of Tumaco, in Narino in southwestern Colombia. Good 

 collections of shells were obtained on Isla del Gallo, a small island in the 

 mouth of the Rio Patia, and also from the mud flats exposed at Tumaco. 



To the naturalist, the highly diversified coast of Ecuador offers un- 

 limited opportunities for faunal studies for nearly its whole length. The man- 

 grove swamp environment of southern Colombia continues into north- 

 ern Ecuador, covering the banks of the numerous esteros around Punta 

 Mangle with heavy forest growth and reaching into the lower portions 

 of the Santiago and Cayapas river systems. There are, however, a few 

 open spots near Puerto Limones where some collecting is possible. At 

 Tola, at the mouth of the Cayapas, the coast changes gradually to a sand 

 beach as the land behind it becomes higher. This condition continues on 

 to Rio Verde and then to Esmeraldas with diminishing patches of man- 

 grove so, except for short stretches, travel by car or truck on the beach 

 is feasible at low water. Similar conditions continue past Esmeraldas to 

 Atacames (a Cuming locality) and Galeras, although at times, large scale 

 land slides off the cliffs at Punta Gorda render a continuous traverse along 

 the shore impassable by any means. The Galeras Peninsula must be crossed 

 in the rear by a foot trail, its shore lined with rock cliffs rising sheer from 

 the waters' edge and are passable only with great difficulty. At San 

 Francisco, a small settlement on the south side of the peninsula, mangrove 

 again makes its appearance in force and extends past Mompiche to Coji- 

 menes. Cojimenes is a small village at the mouth of the river of the same 

 name and at present an outlet for bananas shipped by small boats to 



