662 THE MARINE ANNELIDES OP THE ORDER SERPULEA, 



they are few and large ; as growth proceeds they become more 

 numerous and smaller, the additional lobes being apparently 

 formed by the longitudinal division of the original broad ones as 

 is shewn by two of them being frequently united below. The 

 lobes themselves are frequently, though not always, armed with 

 minute denticles or spinules, a pair on each. Into the hollow 

 of the cup formed by the proximal portion of the operculum fits 

 the distal part, which is also wine-glass-shaped, with the 

 neck attached to the centre of the proximal segment, and the rim 

 also divided into a series of teeth. These distal teeth are much 

 longer than the proximal set, and taper to a fine point laterally 

 and internally each bears seven or eight acute spines. In 

 number they vary from thirteen to twenty. In the centre of the 

 concavity of this distal segment of the operculum is frequently a 

 strong spine like the teeth of the distal circlet and armed with 

 spinules. Usually only one operculum is developed and this may 

 be either the right or the left. Not unfrequently, however, both 

 opercula are equally developed. When only one operculum is 

 fully developed the other is represented by a club-like process 

 containing a pseudohsemal vessel. 



2. Cymospira brachycera. 



Cymospira brachycera, Baird, "On some new species of Tubicolous 

 Annelids in the collection of the British Museum," Journ. Linn. Soc. Zool., 

 Vol. VIII., p. 17, pi. II., fig. 2. 



" Branchiae in spiras quinque convolutae. Operculum magnum, 

 cornibus duobus brevissimis irregulariter dentatis armatum." 

 (Baird.) 



"East Coast of Australia." [Brit. Mus.] 



3. Cymospira Morchii. 



Cymospira Morchii, Quatrefages, I.e., pp. 540 and 541. 



" Caput indistinctum. Branchiae cirris numerosis in basi vix 

 quadrispirali. Operculum tricorne. Collare trilobum. Corpus 

 100 annulis circiter compositum, anterioribus 7. Setee anteriores 

 late limbata). Pro uncinis lamina? leeves." (Quatrefages.) 



