404 PANTHALIS (ERSTEDL 



and their shafts are considerably longer than in front ; they dilate in a spindle-shaped 

 manner (in antero-posterior view, Plate XLI, fig. 16) at the end of the shaft, and then 

 taper to a blunt point. In lateral view (Plate XLI, fig. 17) this region is somewhat 

 spathulate in outline, the tip being broad, with the end of the shaft slightly bent 

 backward, and finely striated. More than the distal half is covered with fine spines 

 (pinnately arranged), which increase in length distally, and finally terminate at the dorsal 

 edge in a long slender whip of such fibres, one being stronger and far longer than the 

 others, and projecting from the midst of a basal series of large hairs (Plate XLI, fig. 17). 

 These bristles (Grannenborsten of Marenzeller) appear to be capable of repair, one 

 presenting two fractures below the tip, yet quite stiff and useful, the callus in each case 

 being more coarsely striated than the normal bristle. In one small example from 358 

 fathoms in the Atlantic these bristles have shorter and more acutely tapered tips, and 

 the spines cover three-fourths of the edge, commencing just above the base. Another 

 and larger example from 516 fathoms (H.M.8. 'Triton') shows similar features. The 

 terminal whip is a true prolongation of the shaft, with lateral spines. 



At the ventral edge is a group of bristles with long shafts as slender as the superior 

 brush-like forms, a well-marked shoulder or curve as in the anterior bristles (which 

 they closely resemble), and a long tapering curved finely spinous tip (subulato-serratse, 

 Kinberg). The spinous rows of the curved region are prominent, while the long tapering 

 region beyond has its spines somewhat longer just after its commencement, and thus in 

 antero-posterior views presents a broader feathered arrangement (Plate XLI, fig. 18). 



The feet retain the fundamentally bifid condition to the posterior end, both spines 

 being present, though the dorsal lobe is only marked by a slight eminence (devoid of 

 bristles), to which the spine goes. All the bristles are greatly elongated, but they 

 preserve for the most part the characters seen in front. Thus the smoothly rounded 

 ventral division has superiorly long slender bristles with the dilated and serrated tip. 

 The shafts of the strong median series are also much elongated, and the dilated tips are 

 densely spinous like a stiff brush, and closely akin to the condition of certain forms in 

 Aphrodita aculeata. No filamentous terminal brush occurs, but the sides of the club- 

 shaped tip are densely bristled, and the spikes project beyond the tip. The filamentous 

 tip may have been abraded in these cases, but this is uncertain. 



An elaborate account of the golden yellow fibrous secretion by the spinning glands in 

 Polyodontes maxillosus, with numerous finely drawn figures, is given by Dr. Hugo Eisig 

 in his beautiful ' Monograph on the Capitellidae,' l and the arrangement seems to be very 

 similar to that in Panthalis. Dr. Eisig considers the fibrous golden yellow secretion as 

 homologous with the spines and bristles of these and other Annelids, and enters into a 

 lengthened description of the structure of similar glandular secretions in both Vertebrates 

 and Invertebrates. The glands are long tubular structures which pour their secretion 

 externally by an aperture in the dorsal papilla above the foot. The threads thus 

 secreted are mingled with mud in the formation of the tube, and Mr. Arnold Watson has 

 described the mode by which the animal ruptures the anterior end, and, throwing it 

 outward, adds layer upon layer in this manner, so as to constitute a massive tube. 



1 Naples, 1887. 



