POTTS— POLYCH.F.TA. 335 



back on head and hidden by nuchal collar. Median tentacle a little longer than lateral ; 

 palps stout, ending suddenly in filiform tip. equal to median tentacle in length. Porsal 

 cirri long uniformly tapering structures, anteriorly much longer than notopodial setse, 

 posteriorly shorter. Elytra closely overlapping, covering whole body, each possessing 

 two oblique longitudinal keels on surface, which is otherwise apparently smooth, but 

 really covered with many minute flattened tubercles (fig. 1). Dorsal setae of insignificant 

 development, distinguished by very slender tips, on which the spines are continued to 

 the very end. Ventral setae with small spur under apex and small number of spinous 

 rows. 



Locality. Reef of Praslin Island, Seychelles. 



In the possession of keels ornamenting the surface of the elytra this species bears 

 a close resemblance to another worm described in this collection, Pohjnoe plutyciiTits, 

 Mcintosh, in which case it is curious to note that one of the specimens is keeled, 

 while the other has no trace of svich a condition. In view of this fact it is questionable 

 how far specific importance should be assigned to the keeled condition in this 

 Lepidonotus. 



11. Lepidonotus pustulatus, sp. n. (Plate 18. fig. 2.) 



Measurements. Specimen incomplete, 20 segments with 10 elytra ; breadth 7 mm. 

 with setae, length 18 mm. 



Head rounded, with two pairs of large eyes, rather ill-defined, so that on one side 

 they have almost coalesced. Tentacles a direct continuation of head, rather small and 

 slender, median tentacle rather longer than lateral. Palps nearly twice as long as 

 tentacles. Elytra (fig. 2) almost circular in shape, anteriorly meeting over head, but 

 posteriorly leaving middle of dorsum uncovered. On the external border a fringe 

 of not very numerous short clavate papillae. Save for the external border, which is 

 free, surface covered with a greenish pigment arranged in very small cells ; minute 

 flattened tubercles occur all over, and posteriorly also a small number of much larger 

 rounded tubercles, or rather " pustules," giving a characteristic appearance to elytra. 

 Dorsal cirri slender and gradually tapering. Dorsal spinose setae very distinctly of two 

 kinds, one shorter with a blunt apex, the other with a slender apex ou which spines are 

 not discernible. In first setigerous segments where setae are shorter spines are continued 

 up to tip ; generally spinose part very strongly serrated. Ventral setae short but stout, 

 with rather restricted spinose region. No spur underneath apex. 



Locality. Eas O, Zanzibar, dredged in 10-15 fathoms ; collected by Mr. C. Cross- 

 land. 



The pustulate elytra which are a marked character of the species resemble those of 

 L. wahlbergi, Mcintosh, which do not, however, possess a fringed border, and are 

 covered with spines, not with tubercles. The very attenuate dorsal setae are perhaps 

 the most typical feature. The species to which it comes closest is undoubtedly 

 L. gymnonotus, recorded by Marenzcllcr and Mcintosh from Japanese waters. 



41.* 



