SABELLIDS. 217 



their cilia. 1 He describes what he terms a cartilaginous skeleton in these branchiae, 

 composed of cells, with a tough fibrous investment like a periosteum. He refers to the 

 chondroid tissue of the organs. 



This family was united with the Eriographididae and the Serpulidae, under which 

 latter title the whole were ranged by De Quatrefages (1865), but it is difficult to see 

 what was gained by this method, which, if anything, increased the complexity of the 

 subject. It is true it led to certain interesting homologies of the organs of the two 

 families, such as that of the tentacles of the Sabellidae with the opercula of the 

 Serpulidae. In his arrangement of the large family thus constituted De Quatrefages 

 employed the operculum, the regions of the body, the branchiae, the tentacles, the feet and 

 the tubes in separating the genera, of which he made twenty-one. Under his first tribe, 

 the Serpulea sabellea, were ranged the Sabellids proper, Oria, Fabricia, Amphiglma, and 

 Protala, whilst in the second division, the Serpulea heterosabellea, were Anamsebsea, 

 Amphieorina and Myxicola. He distinguished these from the former by the supposed 

 indistinct separation between the thoracic and abdominal regions — a misapprehension 

 corrected by Claparede. 



Following De Quatrefages Dr. Johnston (1865) included the Sabellidae under the 

 Serpulidae. Grube (1878), like various previous authors, placed the Sabellidae along with 

 the Serpulidae in his Family Serpulacea, Blainville. This author in 1838 showed that 

 the vessel to the branchial filaments was single. 



Claparede (1868), following Burmeister and De Quatrefages, included the Sabellidae 

 under the Serpulidae as the first tribe of that group, and distinguished from the other 

 tribe by the fact that they have no thoracic membrane whereas the Serpulids have. 

 Moreover, the Sabellids are characterised by the presence of a ciliated median ventral 

 groove, which, passing between the right feet at the posterior part of the thorax, becomes 

 dorsal in that region. This " sillon copragogue " of the Swiss author carries faecal 

 matter to the front, and discharges it from the tube without contact with the mouth. 

 In those species in which the groove is ventral throughout it becomes less and less deep 

 anteriorly and disappears in front, so that when the animal projects its anterior region 

 from its tube at the usual angle the faecal matter is dropped at a distance from the 

 mouth. He corroborated Grube's observation that the blood-vessel to each branchial 

 filament was single, and that the skeletogenous support was independent of the 

 perivisceral prolongation. 



Langerhans (1880) groups the Sabellids under his Serpulacea, but readily 

 distinguishes them from the Serpulids by the absence of the thoracic membrane. He 

 arranges the genera of the Sabellidae thus : 

 I. Tori on the thorax with two rows of bristles. 



A. With a collar. 



a. Branchiae spiral Spirogr aphis. 



b. Branchiae simple. 



a. Sub-terminal branchial eyes. ..... Branchiomma. 



(3. No sub- terminal eyes. 



1 Grube and Claparede, on the other hand, pointed out that in the Sabellids the trunk to the 

 filament was single. 



197 



