Dr. A. Philippi on the genus Serpula. 157 



4. S. vermicularis, L. ? testa tereti, flexuosa, Ifeviuscula, apice libero 

 protensa, rosea ; ore patulo ; carina denticulata dorsali demum 

 obsoleta. Diam. 2i"'. 



Animal branchiis omnino coccineis, filorum multorum ; operculo coc- 

 cineo, crenis plurimis. (Fig. A. Plate III.) 



This species shows with liow little judgement the Serpula; have 

 been investigated. Blainville, ' Diet.' I. c. p. 553, assigns to each 

 branchia seven to eight digitatious, while in the drawing we find 

 on each side twenty-six ! In the description he terms the oper- 

 culum clavate with two minute horns ; but this is the case, ac- 

 cording to pi. 1. fig. 3, ^\4th the operculum of Vermilia trique- 

 tra; and the figm-e of Serpula vermicularis, pi. 1. fig. 1, exhibits a 

 totally chfierent form of operculum, being according to the defi- 

 nition I have given above, that of a true Serjmla. Is it possible 

 to commit greater contradictions ? Thus then, according to Blain- 

 \alle^s description of the operculum, the animal is not a Seipula 

 but must be a Vermilia, Lamarck, which genus Blainville adopts. 

 Cuvier likewise states in the ' Kegne Animal,^ ed. 2. iii. p. 191, 

 (according to INIiill. Z. D.,) that the operculum has two or three 

 small points, in which his species and Miiller's would be a Poma- 

 toceros. 



[It is possible that nos. 1, 2 and 4 should be considered as mere 

 varieties of one species.] 



5. S. aspera. Ph., testa teretiuscula costis circa 7, crenulatis ornata, 

 alba. Diam. 1"'. 



Animal branchiis fuscescentibus aut rubentibus, filorum 8 utrinque ; 



operculo albido, crenis 16 — 24. (Fig. B.) 



AnVermilia scabra. Lam. ? The figure in Delessert's ' Recueil,' 

 &c. is thoroughly bad, and the text in this work is, as is well known, 

 of no assistance whatever. 



6. S. subquadrangula, Ph., testa elongata, subquadrangula, angulis 

 crenato-dentatis, carinis tribus, singulis in medio laterum libero- 

 rum. Diam. f ". 



Animal albidum, branchiis filorum 8 utrinque ; operculo basi aucto, 

 fuscescente, crenis admodum profundis, circa 24. (Fig. C.) 

 The fleshy petiole is not simply conically thickened at the ex- 

 tremity, but first cylindrically and then obconically. 



7. S.venusta, Ph., testa tereti, transversim striata, varicibus pluribus 

 ornata ; alba, ore patulo. Diam. 3"'. 



Animal coccineum ; branchiis filorum frequentium ; operculi crenis 



circa 60. 



The largest species which I have observed and preserved in 

 spuits. The animal is 28"' in length, and 3'" in thickness. 



2. Placostegus, Ph. 

 1. PI. crystallinus, Scac, testa \'itrea, triquetra, demura libera, et 



