Mr. W. Clark on the Chemnitzise. 383 



it supports ttose of M. D'Orbigny ; and it would show that the 

 Chemuitzian animal has not a long retractile proboscis, as Mr. 

 Alder states, and in which point, if it be so, fhemnitzia would 

 appear to differ from Eulima, which has a retractile proboscis. 

 The matter at present is involved in some doubt ; my own im- 

 pression accords with M. Philippi, and I believe with M. Loven, 

 but I fully expect this summer to clear up errors, and throw 

 much light on these points. 



When I stated in the last paper in the April ' Aiinals,^ 1851, 

 that all the Chemnitzice had a tantamount process to those as- 

 signed by ]Mr. Alder as one of the distinguishing characters of 

 his genus Jeffreysia, I thought my discovery a new one ; but I 

 find by Dr. Johiistun^s excellent 'Introduction to Conchology,' 

 from a paper inserted therein, wriUen in 1835 by John Edward 

 Gray, Esq., that that gentleman is, I l^elieve, the orir^inal disco- 

 verer of the flap or process in the opei cula of the PyramidellidtB. 

 I now present a most important quotation from that portion of 

 the paper relating to the opeicula (p. 449) ; Mr. Gray says, — 

 " The opercula of some shells wh'ch have plaits on their pillar 

 are very thin, and are furnished with a moveable flap on the left 

 side of their ante^'ior margin, which passes over the plaits. I 

 first observed this in the common Tornatella, and aiXerwards in 

 Turbo pallidus of Montagu, the genus (Jdostomia of Dr. Fleming, 

 and have since verified it in Pyramidella. The subannular oper- 

 culum of Turbinella cornigera has a notch in the middle of the 

 anterior margin and a plait running from the nucleus, but in 

 this case the flap is not moveable." 



This latter part of Mr. Gray's remarks with reference to the 

 subannular opeiculum, the plait running from the nucleus, and 

 the flap not being moveable, precisely embraces my views of 

 Chem. opalina and Chem. diaphana, in which the flap, as Mr. Gray 

 calls it, is not moveable ; and I found that to be the case in most 

 of the fourteen species of Chemnitziee I have examined ; but in 

 some, for instance the young shells of Chem, pallida, and in 

 Chem. rufa, the flap or apophysis is moveable, or in other words, 

 it is cartilaginous and flexible. These extracts and remarks are 

 strongly corroborative of my determination in the last ' Annals,' 

 April 1851, that Mr. Alder's genus Jejfreysia is superfluous, and 

 its species with the subannular strise on the opercula belong to 

 the Pyramidellar genus Chemnitzia, and are much nearer to the 

 Muricidce than to the Litiorinida, whatever may be the character 

 of the proboscis, which I suspect will turn out to be one of 

 transition or subretractile. 



The definiuon of the Chemnitzian animal, and explanation of 

 the incidents attached to it are so decided, peculiar and impress- 

 ive, that when once it has been seen it will never be forgotten. 



