1909.] NATURAL SCIENCES OF PHILADELPHIA. 335 



One is a female filled with large eggs distinctly visible to the naked 

 eye; the others, including the type, appear to be males. 



Sphaerodorum brevicapitis sp. nov. PI. XV, figs. 13, 14. 



Although considerably larger this species closely resembles aS'. 

 papillifer in general appearance. The type and only specimen, much 

 contracted and distorted, is 39 mm. long, with a maximum diameter 

 without parapodia of 1.6 mm., and has 96 segments. 



Owing to the partial ]3rotrusion of the ])roboscis as a soft bulbous 

 structure the prostomium is crowded dorsad. It appears as a \-ery 

 slight, scarcely distinguishable lol:)e, bearing scattered papillse, of 

 which five, though still small, are larger than the others; three of these 

 are very close together near the anterior margin of the lip; the others 

 are separated by a considerable interval on each side. 



Peristomium likewise indistinct — a short achaetous ring bearing a 

 minute mammilliform papilla on each side. A pair of rather large, 

 widely separated pigment spots, the remains of a pair of eyes, lies 

 ])artly on this segment but chiefly on III. Owing to the condition of 

 the specimen little can be determined about the normal appearance of 

 the segments. The cutaneous papillse, however, are less numerous 

 and smaller than in S. papillifer. They are scattered fairly uniformh- 

 over the surface, becoiTiing more numerous on the parapodia. Pygi- 

 diimi a minute ring bearing a pair of low, broad, mammilliform i)apilla>, 

 besides at least two small, simple papillse. 



Parapodia (PI. XV, fig. 13) in general similar to those of *S'. papillifer. 

 but the parts more widely separated and the neuropodia more slender 

 and cylindrical with a conical apex, rather than simply conical, and 

 ending in a small postacicular lobe. Neurocirri small, subconical 

 processes arising from the posterior ventral side of the neuropodia just 

 at the base of the terminal cone. Spherical organ prominent, ^\ith a 

 thinner cuticle than in S. papillifer, and the papilla borne on the \'eiitral 

 side of the base instead of on the outer surface. Dorsal papilla (noto- 

 cirrus) well alcove spherical organ, small, claviform, with a widened 

 base. 



Aciculum single, rather more slender than that of .S^. papillifer. 

 but similar in form, colorless, the blunt-pointed tip projecting freel\'. 

 Setse in irregular fascicles of usually eight or nine, rather prominent, 

 all compound or semi-compound, becoming widened and flattened 

 distally and then tapering into a hooked tip or appendage \\hich is 

 articulated to the stem by an oblique joint, the absence of which would 

 leave these seta? very similar to those of S. papillifer (PI. X\', fig. 14). 



