152 AMERICAN JOURNAL 



nucleus, and a trenchant angle in the young ; aperture oblong 

 rhomboid ; outer lip in youth striated within ; columella with a 

 callous deposit in front, forming a plate, convex in front and with 

 a well-defined fold. 



This genus, if we may judge from the shell, is decidedly most 

 nearly related to Fuk/ur, and may in brief be described as a 

 Fulgur with abruptly contracted whorls, trenchant at the angle 

 (in the young), depressed spire, and convex intracarinal surface. 

 In the texture of the shell, the columellar fold, the tortuous 

 canal, and the papillary nucleus, the genus agrees with Fulgur, 

 and has even been united Avith that genus by so rigid an ana- 

 lyst as Dr. Morch. The F. coarctatus Sowb. lessens the gap be- 

 tween Fulgur and the genus in question. Yet Dr. J. E. Gray, 

 whose differentiation of genera is often carried to an extreme, 

 treats the type as a 3Iurex ! giving to it however, in 1857, the 

 new sectional name Pyrenella, which is doubtless a substitution, 

 through lapsus memoria, for Pyrella. He claims for Murex 

 "" shell ovate ; spire short, with three or more rounded or spinose 

 varices on each whorl ; mouth ovate ; canal elongate, tubular, 

 spinose externally." As his "■ 31. iSpirilla " has not a "shell 

 ovate," nor "three varices on each whorl," nor "mouth ovate," 

 nor "canal tubular, spinose externally," we are left to wonder 

 why it has in this last, as in all the other memoirs of Dr. Gray, 

 been referred to Murex. We are indeed told that it has " vari- 

 ces rudimentary, unarmed," which, though somewhat contradic- 

 tory to the diagnosis, might be accepted as a modification ; but 

 by the term rudimentary is generally understood a development, 

 however faint, of the character with regard to which the term is 

 used. In the present case, cognizance can be taken of the " va- 

 rices " only by the eye of faith, for they are certainly not evi- 

 dent to the physical one. Dr. Gray may, however, claim that he 

 only followed Schumacher, whose work was published in the 

 year 1817. 



It will be observed that the genus is restricted to the T. spi- 

 rilla. The so-called Fasciolaria porpliyrostoma., Ad. and Reeve, 

 referred to the genus by the Messrs. Adams, appears indeed to 

 be closely related to it, but the subfusiform shell, Avith the con- 

 cave upper surface of the whorls, coronated angle, suboval aper- 

 ture, and the regular concavity of the columelhi, appear to indi- 

 cate that it should be considered as the type of a distinct genus, 

 which he named Streptosijjhon. 



