636 A. JS. Verrill — Turbellaria, N^emertina, and 



Marphysa regalis, sp. nov. 



A highly iridescent, large, robust species, composed of about 125 

 to 130 segments, narrowed close to the head. The branchiae begin 

 at about the 20th segment ; becoming trifid at about the 25th or 

 26th segment, and 4-branched at about the 45th, continuing as a 

 simple cirrus, on a large number of more posterior segments. In 

 the adult some branchiae are 5-branched. 



Head narrowed, with two deeply separated, rounded front lobes. 

 Three median antennae are about equal, tapered, articulated, with 

 about 5 oblong annuli, not deeply constricted ; length about one- 

 half the breadth of the buccal segment ; outer antennae similar, 

 about one-quarter shorter. 



The buccal segment is as long dorsally as the next two, or as long 

 as the next three at the sides. 



From IS to 22 anterior setigerous segments are without branchiae. 

 The first branchiae are usually bifid in the adult, but simple in 

 immature individuals; bifid branchiae continue to about the 25th or 

 26th setigerous segments, where they become trifid, with long, slen- 

 der, nearly equal branches, and these may continue for a large 

 number of segments, but in the fully adult specimens they become 

 4-branched on a number of segments back of the 45th, and a few 

 sometimes have 5 cirri. Posteriori}^ they gradually decrease ; being 

 simple on about 40 segments, and wanting on the last 60 segments. 



The dorsal cirri on the anterior 20 segment;? are rather long, thick 

 at base, rapidly tapei'ed or acuminate distally, and faintly annulated ; 

 in the branchial region they become smaller and more conical. The 

 first pair of ventral cirri are rather long, equal to the setigerous 

 lobe ; a little farther back they became low, broad, verruciform with 

 a small, i^apilliform terminal joint. 



The setae in the branchiated segments ai'e numerous ; in the upper 

 fascicle the longer capillary setae have rather long and slender acu- 

 minate tips; they are accompanied by a number of brush-shaped 

 setae Avith wide ends. In the lower fascicle all the setae are com- 

 pound, and have rather stout stems, with enlarged sublanceolate 

 ends ; blades oblong-lanceolate, the ratios as 1 : 4-5, with the tips 

 strongly bidentate. Each fascicle has a large, black, spiniform 

 aciculum, that of the upper fascicle larger and less acute ; their tips 

 project somewhat, as preserved. 



Color, in formalin, brownish or flesh-color, mottled with darker, 

 with a brilliant iridescence. The surface, under a lens, appears 

 minutely punctate, and is finely specked with whitish dorsall3^ 



