52 K. J. Bush — Two genera of tubicolous Annelids. 



Art. Y. — Notes on the Relation of the two genera of tubi- 

 colous Annelids, Vermilia Lamarck, 1818, and Pomato- 

 ceros Philippi, 1844 ; by K. J. Bush, Ph.D. 



[Brief Contributions to Zoology from the Museum of Yale Univ., No. LXVII.] 



Ik 1844 Philippi described a species from the Mediter- 

 ranean, figuring its operculum (P) under the name of 

 Pomatoceros tricuspis, creating for it the then new genus 

 Pomatoceros, at the same time calling attention to its possible 

 identity with Serpida triquetroides Delle Chiaje '28, which 

 identity was established by Claparecle '69 (p. 182). Philippi 

 also pointed out its resemblance to Vermilia triquetra Lam- 

 arck '18, but on a later page applied this latter name to a form 

 having a different operculum cap, which he also figured (P). 



Among a number (12) of beautifully preserved specimens 

 recently received from the JNaples aquarium, under the name 

 Pomatoceros triquetroides ( Vermilia triquetra)* two have 

 the operculum capped by a low asymmetrical calcareous cone 

 surmounted by a group of three conspicuous tapered spines, 

 well figured (P) in front view by Philippi, as P. tricuspis. 

 Two have a similar but much elongated cone gradually tapered 

 to the narrow truncated tip without spines, well figured (P) in 

 back view by Philippi, f as Vermilia triquetra Lamarck ; one 

 is splitting at the summit, revealing a shorter interior cone. 

 All of the others have the short cone without spines, compara- 

 tively broadly truncated on the end, the tip sometimes elon- 

 gated and indistinctly notched. Similar great variation in form 

 of the operculum cap is found among specimens in the Yale 

 Museum, of Pomatoceros triqueter Linne from Denmark. 

 The same forms were also figured by Sowerby '20 (pi. 1, figs. 

 2 a, b, c, ), as Serpula triquetra Linne;}: ( Vermilia Lamarck, 

 explanation of plate). The various species and even the 

 genera with which these forms, being separated, have been 

 identified by several more recent authors, apparently without 

 establishing other more essential differences, has brought about 

 the present great misconception or misinterpretation of the 

 original application of names. In the two species under obser- 

 vation no generic differences, as the development of the tho- 



* This combination is given by Lo Bianco '93 (p. 86). 



f The operculum is often found with concave base, the wall drawn upward, 

 giving in back view the effect of the median angle shown in Philippi's figure. 



% As the fragment of mollusk to which the tubes of Vermilia represented 

 in Sowerby's figure 2 are attached is presumably that of Pecten maximus 

 found on the coast of England, his species could not have been the true Ser- 

 pula triquetra. Its identity as suggested by Johnston '65, Avith Vermilia 

 conica Fleming '25 and Serpula armata, Johnston (not Edwards + Lutken + 

 Grube), seems not to have been definitely established. 



