APPENDIX. 275 



Vol. iii. p. 242. Chemnitzia elegantissima. 



Mr. Clark has given a full description of the animal of this 

 species in the " Annals of Natural History," for August, 1851. 

 He also describes that of the form pusilla, which would appear 

 to have strong claims to specific distinction. Its foot is longer 

 (than that of elegantissima) and is acute behind (not obtuse as in 

 the allied form)." In pusilla the tentacula " when spread have 

 their membranes united to the extremities, which are minute and 

 pointed, so that they appear in action a single united leaf : in 

 its congener they are more triangular, less, though greatly, mem- 

 branous, and do not unite above half their length, and have very 

 obtuse terminations. The C. pusilla has a palish purple streak 

 on each tentaculum and on each side the rostrum " (i.e. mentum) 

 " in the C. elegantissima both the parts are hyaline-white." 



The shell differs very little from the typical elegantissima, and 

 although long identified with the gracilis and pusilla of Philippi, 

 has hitherto been regarded as its dwarf variety. It is both 

 smaller and more slender, and has rarely more than nine or ten 

 volutions, which are much flattened. 



In some individuals the whorls are high in proportion to their 

 breadth, the suture strongly marked, and the ribs, which are not 

 at all sinuated nor arched (for the most part they are slightly so 

 in elegantissima proper) are so closely packed, that their intervals 

 are mere grooves ; these peculiarities, however, are not present 

 in others. 



The examples forwarded by Mr. Clark having been compared 

 with the specimen of gracilis received from Philippi cannot be 

 distinguished from it ; in others, he writes us word, he can trace 

 the spiral striae (or rather what Philippi took for them, as he 

 observes) mentioned as present in that species ; he considers that 

 both form but one species, for which he prefers the name pusilla. 



Of our British synonyms of elegantissima, that of Fleming pro- 

 bably belongs to this shell ; but almost all our English writers 

 have included both forms under one appellation. 



The Turbo albus of Pennant (Brit. Zool. ed. 4, vol. iv. p. 13, 

 pi. 79, fig. below central group) was apparently a Chemnitzia, and 

 probably the elegantissima of authors. The figure is too bad, and 



