494 PROCEEDINGS OF THE ACADEMY OF [May, 



with certainty. Anus rather small, nearly transverse, widely open 

 and succeeded by a small median ventral tubercle. 



The setigerous tubercles (PI. XXXVIII, figs. 28 to 30) are very 

 small, not elevated on any special muscular band, though appearing 

 at the lateral angles posteriorly, and are well separated throughout. 

 The first 30 somites bear capillary setae only. Spines appear at that 

 point in the ventral fascicle and soon become thick and dark brown. 

 By XL there are usually four of these spines associated with capillary 

 setae, but the number soon becomes reduced to three, the number of 

 capillary setae simultaneously diminishing. From CXX to CL there are 

 two spines and the capillary setae have disappeared ; beyond CL there 

 is one (or rarely two) large, stout, nearly black spine which continues 

 to increase gradually in size. Toward the posterior end a reverse 

 change begins, and behind CCC there are usually two comparatively 

 slender and pale spines. In the notopodial fascicles spines appear later, 

 the first at about L. At about C three small pale spines usually occur, 

 with the capillary setae. The fascicles undergo changes analogous to 

 those just described, but in the same segment the spines are almost 

 always more numerous, not over one-third as large and always asso- 

 ciated with capillary setae. 

 Maldane disparidentata n. s. (PI. XXXVIII, figs. 28 to 31.) 



The length of complete examples is from 100 to 150 mm., and 4 to 6 

 mm. in diameter in the somewhat contracted state; some fragments 

 indicate specimens of larger size. Probably owing in part to contraction, 

 as indicated by a distinct fold of the first setigerous somite which over- 

 laps the head ventrally, the latter is truncated with little obliquity; its 

 V ntral length, including the united prostomium and peristomium, 

 is scarcely one-third more than the dorsal. Cephalic plate broadly 

 oblong-elliptical, its width at least four-fifths its length, the surface 

 smooth and slightly elevated in the center. The frontal ridge low, 

 broad and inconspicuous; beginning just anterior to this elevation and 

 ending anteriorly in the palpode ; its length equal to one-third the cepha- 

 lic plate; posteriorly one-third as wide as the plate, gradually widening 

 for its posterior half, then suddenly expanding into the palpode which 

 is broad, thick, rounded, smooth and separated from the cephalic 

 margin laterally by only a slight emargination. Sensory slits short, 

 sharply defined but inconspicuous. Cephalic margin nowhere much 

 produced, low and thick, probably in part the result of contraction; 

 a pair of lateral clefts divide the posterior one-third from the anterior 

 two-thirds. The former is lower, embraces the latter at the sides and 

 has its margin divided into about fifteen low, broad, truncate teeth, 



