No. 6.^ Pacific Coast Polychacta collected by Alexander Agassiz. 



By Ralph V. Chamberlin. 



In 1859 and the early part of 1860 a considerable collection of 

 Pacific Coast polychaetes was made by Alexander Agassiz in the 

 intervals of his work as Aid on the U. S. Coast Survey. The greater 

 part of the material was secured at Mendocino and Crescent City, 

 California, which are on a section of the coast scarcely represented 

 in more recent collections of polychaetes. Other specimens were 

 secured at San Mateo, Calif, and on the Gulf of Georgia, Washington, 

 and a few at Panama. This collection, though of much interest and 

 value, has remained unidentified until the present time with the excep- 

 tion of a number of species of Nereis described by Ehlers in his Die 

 Borstenwiirmer (1864-1868). The following is a complete list of the 

 species in the collection at present identifiable. In addition to the 

 specimens collected by Mr. Agassiz himself, notes upon some material 

 secured by others on the Pacific Coast during or near the same period 

 of time are also included 



Amphinomidae. 

 1. NoTOPYGOS maculatus (Kinbcrg). 



Lirione maculata Kinberg, Ofvers. K. vet. akad. Forh., 1857, 14, p. 12. 



Two large specimens from Panama, one collected by Dr. G. A, 

 Maack on the Darien Expedition and one by Q. F. Davis (received 

 M. C. Z. in 1862) are referred to Kinberg's species, the type of which 

 came from the same locality, on the assumption that this type is a 

 very young specimen. Kinberg's^ account is so meager that, were the 

 present specimens not from the same locality, they would scarcely 

 be referred with much confidence to this species. These specimens 

 are much larger than the type, approaching rather crinitus or splendens 

 in size. One consists of thirty-three and one of thirty-five segments. 

 The dark maculations and stripes are strongly developed. The 

 Philippine specimens referred by Grube (Annulata Semperiana, 1878, 

 p. 8, pi. 1, fig. 3) to this species are not conspecific with the Panama 

 form, as shown by their much simpler branchiae, different coloration, 

 and other features. 



