NO. 3 HARTMAN : POLYCHAETOUS ANNELIDS 321 



The prostomium is depressed, spatulate, with broadly rounded, 

 frontal margin, unmarked save by a pair of elongate, triangular areas 

 at the sides of the middorsum (pi. 28, fig. 10). There are no visible eyes. 

 The paired palpi are papillated, resemble those of other species. 



Parapodia are inconspicuous throughout, provided w^ith flattened 

 lamellae in both rami. Those of the anterior region are as large as, or 

 somewhat larger than, those in posterior segments. In the anterior region 

 they are distinctly postsetal in position ; in the posterior region they are 

 interramal, though still postsetal (pi. 28, fig. 13). Dorsal and ventral 

 cirri appear to be absent. Parapodia of the first 9 setigers have only long, 

 pointed setae (pi. 28, fig. 12) ; those of the ninth resemble those in front. 

 Posterior parapodia, from the tenth, are provided with spreading fascicles 

 of hooded uncini (pi. 28, fig. 13) in which the distal end is bidentate, the 

 secondary tooth thick and more conspicuous than usual (pi. 28, fig. 14). 

 The posterior end terminates in a pair of lateral, digitate cirri at the 

 sides of the anal aperture (pi. 28, fig. 11). 



M. calif ornka is characterized in having the prostomium anteriorly 

 rounded, with simple, triangular swellings on its dorsal surface; setae 

 of the ninth segment are simple capillaries, resembling those of the first 

 few segments; uncini are distally bidentate, the secondary tooth thick, 

 conspicuous; dorsal and ventral cirri are seemingly absent; parapodial 

 lobes are small throughout. It is distinguished from other species as indi- 

 cated in the key (see above). Its color in life is dull pale pink. 



Holotype. — AHF no. 56. 



Type locality. — Mission Bay, California. 



Distribution. — Mission Bay, Anaheim Slough and Newport Bay, 

 California; intertidal. 



LongOSOmidae, new family 



The only known representative, Longosoma catalinensis, new genus 

 and species, is characterized in having an anterior region of 9 setigerous 

 segments, each provided with notopodia and neuropodia and from the 

 second with a pair of long, tentacular cirri ; this is followed by a region 

 in which the segments are greatly prolonged (hence the generic name). 

 In so far as known, setae are entirely simple, pointed, save some in the? 

 first neuropodium which include heavier, falcate ones. The prostomium 

 is a simple, spatulate lobe, without appendages. The proboscis is a soft, 

 eversible sack. 



