SABELLIDES AND SERPULIDES 249 



Spirorbis carinatus Montagu 1803. 



As already stated (p. 241), there is considerable doubt in regard to 

 this species. The form described by Fleming (1825) is certainly very 

 similar to S. quadrangularis Stimpson, but it is not improbable that 

 both species occur on the English coast. In the Yale University 

 Museum are two unicarinate, regularly coiled forms, one dextral, 

 attached to a valve of Anomia from Guernsey, England, and to a stone 

 from Birterbuy Bay, Ireland, and the other sinistral, attached to a 

 worn valve from England; neither is like the carinate, triangular, 

 immature form of S. quadrangularis from Eastport, Maine, and 

 from Greenland. 



Spirorbis sulcatus Adams 1797; S. granulatus Montagu 1803, non 

 Linn6 1767. pi. XLI, fig. 9; pi. XLIII, figs. 8, 19. 



Attached to a Haliotis tuberculata from Guernsey, England, and to 

 a worn limpet shell from Birterbuy Bay, Ireland, are numerous thick, 

 more or less regularly spirally coiled, sinistral tubes, having a deep 

 groove on top of the whorls, when adult, with a large rounded carina 

 on each side, the inner one defining the small central cavity ; in very 

 large specimens another much shallower groove appears on the side of 

 the whorl, with a much smaller carina or thread along its lower edge. 

 The surface, when perfect, has considerable luster. This species is 

 much larger and thicker than the dextral tricarinate form identified as 

 S. heterostrophus, and is without question the S. granulatus Montagu 

 1803, non Linn6 1 767, and therefore must take the name sulcatus, used 

 by Adams 1797 (Linnean Transactions, in, p. 254), non Lamarck 

 1818. 



By the use of potash solution the dried animals were taken from 

 some of the tubes, and the calcareous plate on the operculum and the 

 seta were found. 



Spirorbis validus Verrill 1874. pi. xxxvn, figs. 5, 6, 7, 8, 10, 32 ; 



pi. XLIV, figs. 11-14. 



This, the largest of all species of Spirorbis, varies greatly in its 

 manner of coiling, there being a marked contrast between the regular 

 si MM nil form figured by Levinsen as S. verruca Fabr. and others, 

 where the whorls lie one above the other, forming a high irregular 

 spiral. No difference, however, could be found in the essential 

 characters of their animals. In all the specimens examined, the 

 branchiae number 13 (in very large adult forms Verrill counted 15) 

 and all the setae have long, slender, finely serrate, tapered blades. 



