MALDANELLA FIBRILLATA. 413 



MaLDANELLA FIBRILIiATA, Sp. nOV. 



Plate 72, fig. 1-6; Plate 73, fig. 1-2. 



The preserved specimens are a rather dilute light brown, appearing darker, 

 greenish black, in parts where the alimentary canal is seen through the body- 

 wall. The anterior borders of the anterior somites may be whitish. 



The body in general is cylindrical, but much widest in the anterior region 

 and decreasing caudad to the slender caudal region. Greatest diameter of the 

 largest specimen, 5.5 mm. Composed of nineteen setigerous somites, followed 

 by three non-setigerous ones in addition to the funnel. 



Prostomium and peristomium completely fused. Head obliquely truncate 

 anterodorsally, as usual, at an angle of somewhat more than 45°. Typically 

 from somewhat more than twice to somewhat less than twice as long ven- 

 trally as dorsally. Head-plate subelliptic or ovate in outline. The raised 

 limbate margin well developed all around excepting the anterior interruption, 

 or notch, in which is embraced the anterior end of the median ridge. Free 

 margin of limbus entire and smooth. Median ridge low, distinct caudad to 

 where the plate is crossed by the transverse depression, or furrow, behind the 

 middle. From the middle caudad on each side a series of three sulci, each of 

 which extends from the middle ectad, or cephaloectad, or these sulci sometimes 

 more or less united across the middle. Nuchal furrows nearly straight or but 

 Uttle curved, subparallel, excepting at the anterior end where each is bent out 

 abruptly laterad, the ends hooked. (Plate 71, fig. 1, 2). 



Mouth strictly ventral, surrounded by the usual elevated border, which is 

 crossed by radiating sulci, the elevated border incomplete on the anterior side, 

 where between its free ends it embraces alow, triangular elevation, or prostomial 

 lobe, the apex of which is continuous with the anterior end of the median cephahc 

 keel above. Immediately caudad of and mesally tangent to the buccal ring is 

 a sharply impressed transverse sulcus, which extends upon each side to a shallow 

 longitudinal furrow. 



The first somite caudad of the head is typically clearly longer than wide 

 (in about ratio 9:7). The second somite equal in length and breadth. The 

 third clearly wider than long (in ratio 5:7). The fourth often shortest, being 

 but 1.75 mm. long, with a width of 2 mm., though in some the third is shorter 

 than the fourth. From the third or fourth the somites increase in relative 

 length, the seventh somite in the measured specimen being 3 n\m. long and 4 nmi. 



