498 Dr. Henry Woodicard — On a new Loricula. 



the mode of growth of Loricula being always prone, from the time it 

 first abandoned its free-swimming hirval existence and became fixed 

 at the initial point («), only the capitulum retaining its valves 

 complete on both surfaces, so as to enable it to open and close its 

 body-cavity and allow the cirri to be freely protruded and retracted 

 at pleasure. Darwin has himself stated that "in Loricula the 

 attachment was probably by one lateral face of the lower part of the 

 peduncle, for it is by no means unusual for the cement-stuff (even 

 "when proceeding only from the two original central orifices, where 

 the prehensile antennae of the larvae may still be found) to encroach 

 largely on the peduncle, and thus fix it down. The calcareous scales 

 of Pollicipes and the horny spines of Lbla may often be found thus 

 embedded and firmly fixed to the supporting rock ; it is, moreover, 

 possible that in Loricula the cement was poured out of orifices 

 specially situated on one side of the peduncle, as takes place along 

 the rostral margin in Scalpellum viilyare and high up on both sides of 

 the peduncle in Lepas fascicular is ^'' (Darwin, op. cit., p. 84). 



Mr, Darwin states that Mr. Wetherell's original type-specimen 

 which he so carefully described was found "embedded outside the 

 cast of an Ammonite" (op. cit., p. 82), from which it appears he did 

 not quite realize that it was adhering to the shell and parasitic upon 

 the Ammonite, as Coronula haltenaris attaches itself to the skin of the 

 whale, and Chelonohia testudinaria and C. caretta affix themselves to 

 the carapace of the turtle to-day. 



The abundant evidence now obtained from the Chalk of Bohemia 

 and the Chalk of Kent as to the habit of Loricula to live attached to 

 the shells of Ammonites is conclusive that it was always firmly fixed 

 by one side of its peduncle, and that in all probability the calcareous 

 scales were only developed upon the upper exposed surface. 



In connection with this remarkable Joricated form of Cirripede 

 Loricula it may not be uninteresting to quote the observations of 

 Monsieur A. Gruvel, who has devoted so many years to this group : — ' 



"It is impossible for us to arrive at an exact idea of the form under 

 which the first ancestor of the Cirripedia showed itself after the 

 initial Cypris-state. In the present condition of our palaeontological 

 knowledge of these animals, the first traces which remain to us are 

 met with in the Silurian and Devonian strata of Europe and North 

 America by those calcareous scales, very similar in appearance, which 

 were considered by Professor de Koninck as the plates of Chitons 

 ( Chiton WrigJitiamis), by H. AVoodward as peduncular scales, and by 

 J3arrande as part of the capitulum of a Cirripede. 



" Our opinion is that they are the remains of the complete imbri- 

 cated covering of a primitive Cirripede, first correctly designated by 

 H. Woodward under the name of Turrilepas. The real animal may 

 be said to have been enclosed in this species of scaly cylinder, which 

 afforded only a poor protection to its appendages and soft parts. To 

 furnish a more efficient shelter, the plates of the upper row were 



' " Monographie des Cirrhipedes ou Thecostr.ices, " par A. Gruvel, Universite de 

 Bordeaux. Roy. 8vo, pp. x + 472 = 482, avec 427 figures in text. Paris: 

 Masson & Cie., 1905. 



