188 PROCEEDINa^ OF THE NATIONAL MUSEUM. voi,. :^7. 



ports of Guayaquil, Paita, Callao, and Valparaiso have naturally 

 been much more thoroughly explored than others. The careful col- 

 lecting wliich would obtain the smaller species is not recorded to 

 have been done anywhere at all. 



Dredging also is practicable with difficulty, except in the shel- 

 tered harbors, which occur so rarely on this coast, or by the aid of a 

 large steamer, which could be had only under government auspices 

 on account of the great expense involved. 



The small lots of material derived from the mud which came up 

 on the anchor of the U. S. Bureau of Fisheries steamer Albatross at 

 one or two points, show that proper exploration will certainly reveal 

 the presence of many small species, new or extra limital, which are 

 at present unknown. 



In the preparation of this list I have endeavored to give a refer- 

 ence to the original description and to the best available figure or 

 figures. In determining what species should be included I have 

 depended somewhat upon the known characteristics, as regards 

 distribution, of the groups to which the species belong. For instance, 

 if I found a species reported from Guayaquil and belonging to a 

 widely distributed group, such as the Phohdidse, though not actually 

 reported from a Peruvian locality, I have not hesitated to include 

 it, knowing that in all probability it will be found on more thorough 

 search in Peruvian territory. There can be little doubt that a large 

 number of the more mobile of the Panamic species reaching the Bay 

 of Guayaquil will be found to have extended their range more or 

 less within the northern border of the Peruvian Province, just as a 

 certain number of the characteristic Magellanic species have traveled 

 beyond their strict limits and mingle with the southern members of 

 the Peruvian fauna. Species properly belonging to the Panamic 

 Province and not reported as far south as Guayaquil or the Gala- 

 pagos Islands have been omitted from the list. 



It will be observed that the list contains only a few minute species. 

 Doubtless many of these exist, and will be found when carefully 

 sought for, but, as previously indicated, the majority of collectors 

 seem to have confined their attention to the more conspicuous 

 species. 



I have included a certain number of pelagic forms, Cephalopods, 

 Pteropods, and Nudibranchs, which are not strictly littoral, but are 

 found occasionally thrown on the beaches or are captured within a 

 short distance of the shore. And since collectors are certain to obtain 

 them in their search for mollusks, I have added at the end of the 

 list of Mollusca a list of the littoral Brachiopoda, some of which are 

 so common on these shores. 



In any first census of this kind some species will be included which 

 later investigation will exclude. I have rejected a number of Tschuch's 



