142 PROCEEDINGS OF THE ACADEMY OF [1892. 



A NEW SPECIES OF PYCNOGONUM FROM CALIFORNIA. 

 BY .1. E. IVES, 



In a collection of Crustaceans and Echinodernis from San 

 Diego, California, recently sent to me for determination by Mr. 

 Frederick Stearns of Detroit, there is an apparently iindescribed 

 species of Fycnogonu7n. It is of especial interest owing to the fact 

 that only a single species belonging to the group of the Pantopoda 

 has been described from the Pacific Coast of North America.^ 

 Although only two species are thus now known from the We^-t 

 Coast it is probable that it will be found in the future that a number 

 of species exist on these shores. Professor Edmund B. AVilson- has 

 enumerated fifteen species from the New England waters, and it is 

 possible that as many may be found upon the Pacific Coast. 



Five specimens were sent by Mr. Stearns. As none of them 

 possess ovigerous legs I presume they are all females. 



The species has been named after the collector. To the liberality 

 of the same gentleman I am indebted for the preparation for publi- 

 cation of the accompanying plate. 



The species may be characterized as follows : 



Pycnogonum Stearnsi n. sp. 



Body broad and flat. Lateral processes with scarcely any inter- 

 val between them. 



Proboscis sub-cylindrical, slightly swollen in its anterior half, but 

 contracting somewhat at its extremity, about one-third the total 

 length of the body. 



Each cephalothoracic segment with a prominent tubercle dorsally 

 in the median line on the posterior border and a somewhat smaller 

 tubercle on the outer edge of each lateral process ; first segment 

 about two-thirds of the length of the proboscis, with a not very 

 broad, slightly constricted neck ; second, third and fourth segments 

 respectively equal to about two-thirds of the length of the first ; 

 posterior borders of the segments slightly elevated. 



Oculiferous tubercle bluntly conical ; eyes black, small, nearly 

 equally spaced ; the posterior pair slightly further apart than the 

 anterior pair. 



'^ Amniothea longicatidata Stimpson, from Puget Sound, (Proc. Acad. Nat. Sci. 

 Phila., 1864, p. 159.) 



^Report U. S. Comm. of Fish and Fisheries, 1878 (1880.) 



