1910.] ' NATURAL SCIENCES OF PHILADELPHIA. 373 



successively longer and the line of attachment, which extends from the 

 middle to the lateral margin, shifts to a more posterior position. 

 Those of the last pair are nearly three times as long as wide, tapered 

 posteriorly and are attached about one-fifth of their length from the 

 anterior end. The}^ fold roimd the slender cavidal region and reach 

 bej'ond the anus, the edges meeting to form a nearl}' complete tube. 



Owing to the rigidity of the dorsal spines and my desire to injure 

 them as little as possible the dorsal fimbriated organs were incom- 

 pletely studied. Apparently they begin on VI and occujiy all cirrifer- 

 ous somites as far as XXVIII, occurring in the usual position near 

 the posterior border of the segments at the level of the lateral border 

 of the elj^trophore. They are small and thin, compressed and deeply 

 fiml^riated, the middle ones bearing seven to nine rather long, simple 

 or bifid cirriform papillae (PI. XXXI, fig. 65). 



Parapodia of the usual form, biramous. Neuropodium stout, 

 supported by a single very stout aciculum, truncate, rough and at the 

 end stepped for the three series of setse, the surface, except dorsally 

 densely covered with spherical papillae of various sizes but averaging 

 larger than those on the ventral surface of the segments. Notopodium 

 a low, thick ridge prolonged to the dorsum. Neurocirrus arising from 

 a low cirrophore located somewhat distad of the middle of the neuro- 

 podium and covered with crowded spherical papilhe of the largest size ; 

 style smooth, rather slender, tapered to a slightly bulbous tip which 

 reaches to about base of middle series of seta^. Xotocirrus with large 

 cylindroid cirrophore arising just behind the ventral fascicle of noto- 

 podial setae; style reaching to about tip of second largest spine of this 

 group, slender, smooth, tapered to a distinct subterminal enlargement 

 beyond which is a constriction and terminal ball. Peristomial para- 

 podia (PI. XXXII, fig. 67) small, slender and directed forward, sup- 

 ported by a single aciculum which terminates in the somewhat enlarged 

 end bearing three dense tufts of fine capillary seta*. At the caudal end 

 both rami become free and prolonged laterally and the notopodium 

 lamelliform with a prominent acicular process, while the notocirri are 

 relatively longer with very conspicuous terminal bulbs. 



Neuropodial setae in the usual three horizontal series. On middle 

 segments the ventral series consists of five or six equal, brownish 

 yellow, rather slender and slightly ciu'ved setae, the end (Pi. XXXII, 

 figs. 72 and 73) enlarged, tapered to a slightly hooked, acute tip and 

 usually bearing a pair of small spurs and a few scattered tubercles. 

 Middle series of three, brown, becoming stouter caudad. all smooth, 

 gently curved, tapered withovit evident enlargement (fig. 71). Porsal 



