36 MacFarland — Preliminanj Account of Dorulidse. 



been made at various times during the year for several years. 

 The most of them have heeen secured by shore collecting, the 

 littoral fauna being exceptionally rieli and the area exposed at 

 low tide l)eing large. Some liavc been taken by dredging, Imt 

 extended systematic work by tliis means has not yet been 

 carried out. The material secured l)y the dredging operations 

 of the U. 8. Bureau of Fisheries steamer Albatross during the 

 spring of 1904: will l)e reported upon in another place. 



\Vith the exception of tlie early and fragmentary papers of 

 Cooper and Stearns and the later ones of Bergh upon Alaskan 

 Nudibranchs, the Californian Opistholu-anchs are practically 

 unknown. To this fact is due the large number of new species 

 listed . In no group is the necessity for full and careful anatomical 

 study more necessary as a basis for specific description than in 

 the Opisthobranchiata. In many cases even the genus to wdiich 

 a specimen belongs can not lie made out by general external 

 characters alone. The practice of basing new species upon such 

 superficial and variable characteristics as form, color and size 

 alone can not be too strongly condemned. In every case here 

 listed, with one exception, a careful morphological study has 

 been made, in many instances aided by serial sections, and the 

 complete descriptions will be fully illustrated by plates in the 

 final papers. The general systematic arrangement as proposed 

 by Bergh (1892) has been followed. 



The following is a list of the Doridida' thus far taken : 



NUDIBRANCHIATA HoLOHEPATICA . 



I. Doridida3 cryptobranchiatse. 



1. Archidoris viontereyensis (Cooper). 



2. Montereina nohilis gen. et sp. nov. 



3. Discodoris heathi sp. nov. 



4. Rostanga pulchra sp. nov. 



5. Diaidula sandiegcnsis (Cooper). 



6. Aldisa sanguinea (Cooper). 



7. Cadlbia marginata sp. nov. 



8. Cadlina fiavomaculata sp. nov. 



9 . Chromodoris porter% Cockerell . 

 10. Doriopsis fulva sp. nov. 



