332 PEECT SLADEN TRUST EXPEDITION, 



setae to be protrusible at will, and supposes differences ia the state of retractioii to be 

 responsible for the separation of this species and i. indicus, Kinberg. 



The elytra, which have a curious granulated appearance, do not cover the whole of the 

 dorsum except posteriorly. Where the back lies exposed, there is a complicated pattern 

 of black pigment with strongly marked transverse lines. The colour of the elytra 

 themselves varies greatly with the locality. In the specimens from Hulule, Male Atoll, 

 a dark green pigment may occupy nearly the whole of the elytra, only a small patch on 

 the outer margin remaining unpigmented. The worms from Saya de Malha display a 

 reddish pigment rather diffusely spread over the elytron, but concentrated round the 

 tubercles and patches on inner margin. A similar darker pigment is found in the 

 Zanzibar specimen. 



In all the elytra the same type of ornamentation prevails. There are spherical 

 tubercles (" pustules " of Willey), wiiich may either be large (when they are developed most 

 numerously on the inner half of the elytron) or minute (when they are found crowded 

 together on the outer border). The outer border with the minute tubercles is thinner 

 than the rest of the elytra, and in the specimens here described had characteristically a 

 rather shrivelled appearance. 



■ There is a gradual passage between the smaller and larger tubercles. In both there 

 is a tendency to a keeled condition, l)ut this is developed most usually in the smaller 

 kind. These latter may also have small thorn-like processes on the keel, giving a comb- 

 like appearance. 



The large tubercles reach their greatest development in the specimen from Zanzibar. 

 The first two elytra differ from the rest in showing long chitinous processes ending 

 bluntly ; in the second elytron these arise from a crest-like structure. In the following 

 elytra the tubercles are of the typical development. In the worms from Hulule, Male, 

 the tubercles are neither so large nor so crowded as in the other forms of the collection. 



Localities. Saya de Malha, 26 fathoms ; one specimen. Hulule, Male Atoll ; two 

 specimens. Mamaduwari, S. Mahlos ; a single large specimen. Zanzibar, 20 fathoms ; 

 one specimen. 



8. Lepidonotus cristatus (Grube). 



Polyno'e cristata, Grube, Jahresber. der Schles. Gesellscli. 1875, p. 62, and Beitrage zur Anneliden- 



fauna der Philippinen, 1878, p. 27, taf. 2. fig. 3. 

 Lepidonotus cristatus, Mcintosh, 'Challenger' Reports, Polychaeta, p. 67 [Torres St.] ; Gravier, 



Nouv. Arch, du Mus. Hist. Nat. ser. 4, t. iii. 1901, p. 210 [Aden, Perim, Djibouti] ; Willey, 



in Herdmau, Ceylon Pearl Oyster Report, Polychaeta, 1905, p. 249 ; Malaquin, Rev. Suisse de 



Biologie, t. xv. 1907, p. 345 [Amboyna, Malay]. 



Measurements. One of the largest (Chuaka Head, Zanzibar) was 48 mm. long, 19 mm. 

 broad with sette. Gi-avier's measured specimen from the Red Sea was 37 mm., while 

 the Ceylon worm described by Willey was 43u mm. 



Gravier's recent description is very full, though based on very few specimens. The 

 present examples differ only in certain characters of the elytra, which are exceedingly 

 variable throughout the species. Individuals are easily recognised as belonging to this 



