156 Dr. A. Philippi on the genus Serpula. 



'Diet.' xlviii. p. 560*. [The description whicli Risso gives in 

 liis 'Hist, de FEiu*. Merid.' iv. p. 405. is quite romantic, and 

 does not in tlie least agree ^nth the statements of Cuvier in 

 'Regne xVnimal/ ed. .2. vol. iii. p. 192, whose description is 

 exactly in accordance with my own observations, which will be 

 detailed under bl] 



b. The branchise simply fan-shaped. Psygmobranchus, Ph. 



I cannot agree withCmder in referring the last section, to which 

 I have applied the name Apomatus, to Sabella. I would not lay 

 any great stress on the fact that the Sabellcs form a membranous 

 or coriaceous tube, while Ajjomatus forms a calcareous one ; but 

 I consider of great importance the fact, that in the Sabellce all the 

 rings of the body are formed ahke and are provided with similar 

 bundles of bristles, while in Apomatus, precisely as in Serpula, 

 the first seven fasciculi of bristles are fixed in a membranous ex- 

 pansion, of which not a trace was indicated in the Sabellce ob- 

 served by me. 



I will now pass on to the characters of the individual species. 



1. Serpula, L. {sensu stridiori). 



1. S. echinata, Gm., testa teretiuscula, protensa, flexuosa, rosea, 

 transversim rugosa, carinis denticulatis, echinata. Diam. 2"'. 



Animal branchiis albo coccineoque fasciatis, filorum (in utraque) 30 

 et ultra, operculo rubro. Gm. p. 3744 ; Gualt. t. 10 R. ; Mar- 

 tini, 1. f. 8. 



2. S. pallida, Ph., ^e^^a teretiuscula, protensa, flexuosa, pallida rosea, 

 carina mediana conspicua, lateral! utrinque obsoleta, striisque in- 

 crementi tenuibus subaspera. Diam. \\"'. 



Animal branchiis albo coccineoque fasciatis, filorum pauciorum quam 

 in antecedente, operculo albido. 



3. S. triquetra, L. ? .-' testa triquetra, flexuosa, alba, altero, latere tota 

 adnata. Diam. 2'". 



Animal branchiis albo coccineoque fasciatis, filorum circa 30 ; oper- 

 culo coccineo, crenis circa 24 (according to the drawing ; I forgot 

 to notice the number of folds). 



I do not however think that is the Linnsean species. Linnaeus 

 has not described the animal, and only saw small indi\iduals ; the 

 subsequent citations of Baster, copied by Martini, Gualtieri and 

 others, do not exactly correspond to my species, as they represent 

 the shell much thinner. It should also be observed, that the shells 

 of Serpula triquetra, Vermilia triquetra, and Pomatoceros tricus- 

 pis are difficult to distinguish without the animals. Would it 

 therefore not be better to banish entirely the name Seipula tri- 

 quetra of Linnseus ? 



* The figure of Seba (i. t. 29. fig. 1, 2) does not agree, as already ob- 

 served by Cnvier, witli the diagnosis; it wants the disque of Cuvier or the 

 thorax, " egalant au moins la moitie de Tabdomen." 



