1904.] NATURAL SCIENCES OF PHILADELPHIA. 493 



placed on a wide elevated band, the dorsal margin of which rises 

 prominently about the notopodial tubercles and bears the branchiae on 

 its edge. The usual spines and capillary setse are present, distributed 

 as follows: Anterior to somite XL the latter only occur, but at XL 

 or thereabout small, nearly colorless spines appear among the capillary 

 bristles in the neuropodial fascicles; by L there are usually five, quite 

 distinct and dark colored, though small; they alternate with the setse, 

 and as the latter diminish the former increase in number, the maximum 

 of six being found from about C to CL, behind which the capillary setse 

 have nearly or quite disappeared, and the number of the spines be- 

 comes again reduced to four or five, a number which remains constant 

 to the end, though further diminution in size occurs. In the notopodial 

 fascicles the spmes are smaller, slightly more numerous and first appear 

 a little more caudad than in the ventral fascicles, 



Cirratulus luxuriosus n. s. (PI. XXXVIII, figs. 28 to 31.) 



Form slender throughout, thickest at about end of anterior third 

 (somite C), tapering thence very gently to posterior end. The type 

 and largest specimen is 110 mm. long and 4.5 mm. in diameter at somite 

 C. In the best-preserved specimens the body is strongly convex above, 

 concave below and angulated at the setse levels, particularly the neiu-o- 

 podial, Prostomium about three-fifths as long as broad, rounded 

 anteriorly, depressed, slightly retracted within the peristomium, 

 grooved below in the middle line, thus leaving a pair of lateral palp- 

 like thickenings which bound the mouth above; no eyes nor sensory 

 slits apparent. Peristomium somewhat inflated, about twice as long 

 as the prostomium and divided into two or three annuli. Setigerous 

 annuli numerous (358 in the type), all very short and distinct, those of 

 the posterior third rather longer and with faint indications of irregu- 

 lar division into two wings. The branchise form a conspicuous tangled 

 mass, and even in the alcoholic specimens are very long, equalling ten 

 times the diameter of the body but, unlike C. spirabranchus , exhibiting 

 little tendency to coil spirally. They begin on the first setigerous 

 somite in contact with the notopodia above, but continually rise to a 

 higher level, until toward the posterior end they are much nearer to the 

 dorsal middle line than to the setse. To the 200th somite at least a 

 pair of branchise occurs on every somite, but for the next 70 or 80 

 on every second, third or fourth somite only; there is no diminution in 

 size posteriorly. The special branchise are in a pair of close tufts 

 crowded on the sides principally of the fourth setigerous somite. The 

 number appears to be 12 or 14 on each side, but cannot be ascertained 



