22 DR. W. BAIBD ON NEW TUBICOLOUS ANNELIDES. 



Several specimens of this small species of Serpula are in the 

 collection of the Museum, the slender tubes creeping on frag- 

 ments of old oyster-shells. The operculum is the only part of the 

 animal preserved, as the specimens were transmitted in a dry 

 state. Like that of the other known species of true Serpula, it is 

 finely crenated on the margin. The crense are twenty in nvimber, 

 but the grooves externally are confined to the surface of the disk 

 itself, and are not extended to the pedicel or stalk. The tube is 

 slender, nearly round, with only a slight keel running longitu- 

 dinally along its dorsal siirface. It is white, the mouth is nearly 

 circular, and the shell itself is strongly marked along its whole 

 length with transverse flexuous stria? which encircle it. 



The specimens in the collection are grouped together on the 

 old oyster-shell, and mixed up with numerous specimens of zoo- 

 phytes, Alcyonia &c. Most of them are more or less incrusted 

 with these ■ substances. Length of the tixbe about 16 lines ; cir- 

 cumference about 1 line. 



Hub. New Zealand. (Brit. Mus.) 



EXPLANATION OP PLATE II. 



Fig. 1. Cymospira tricomis, operculum. 



2. C. hrachycera, operculum. 



3. C MacGillivrayi, mouth of tube, in coral. 

 4, 5. Puniatostegus BowerhanJci, operculum. 



6. Serpiila Julcesii, operculum. 



7, 8. S. Narconensis, operculum. 



9. S. Zelandica, operculum. 



10. Eupomatns Boltoni, operculum. 



11. Galeolaria decumbens, operculum. 



