332 GENERAL SUMMARY TO 



power of partially protruding its arms, as I have repeatedly observed in North-Carolina 

 and Japanese species. Terebratulina can only protrude the cirri." 1 



In the ' Transactions of the Zoological Society,' vol. i, pi. xxii, fig. 14, Professor 

 Owen gives a figure of Bhynchonetta psittacea, in which he represents one of the arms 

 unfolded. Grundler figured the arms as far back as 1774 (' Naturforscher,' ii, pi. iii, 

 figs. 3 and 4). 



Lucas Barrett says* that Terebratulina caput-serpentis, of which he obtained living 

 specimens daily during two months, protrudes its cirri further than any of the others 

 {Waldheimia cranium, &c). "The cirri on the reflected part of the arms are shorter 

 than those on the first part. The cirri were almost constantly in motion, and were 

 often observed to convey small particles to the channel at their base. When placed in a 

 small glass of sea water the valves gradually opened. Individuals remaining attached to 

 other objects manifested a remarkable power and disposition to move on their pedicles. 

 Detached specimens could be moved about without causing the animal to close its valves. If 

 any of the protruded cirri were touched the cirri were retracted and the valves closed with 

 a snap, but soon after opened again. When the oral arms were retracted the cirri were bent 

 up, but were gradually uncoiled and straightened when the shell was opened, before which 

 action the animal was often observed to protrude a few of its cirri and move them about, 

 as if to ascertain if any danger threatened. Only on one occasion a current was perceived 

 to set in on one side between the two rows of cirri. I had been attempting to ascertain 

 the existence of currents by introducing small quantities of indigo into the water sur- 

 rounding the animal with a camel-hair brush ; three times the water was forcibly drawn 

 in, and particles of indigo were seen to glide along the groove at the base of the cirri in 

 the direction of the mouth." He adds, p. 258, "As in Waldheimia with a long loop, 

 the oral arms are so fixed to the calcareous skeleton as to be incapable of motion, 

 except at their spiral terminations ; it has been supposed that these conjoined spiral ends 

 could be unrolled, like the proboscis of a butterfly, but I never saw any disposition of 

 the kind manifested. Waldheimia cranium is more lively than T. caput-serpentis, 

 moving often on its pedicle, also more easily alarmed ; the cirri are not protruded 

 beyond the margins of the valves : when the shell is closed they are bent up. In Crania 

 anomala the cirri are protruded, but not the arms, beyond the margin of the shell." 



Every observation in connection with the animal in life is of the greatest importance 

 and should be carefully noted ; thus Dr. Gwyn Jeffreys, who has also watched Terebratulce 

 alive, says (' Brit. Conch.,' vol. ii, p. 8) that they were incessantly opening and folding 

 their brachial or labial appendages, and drawing and sucking-in by means of the whirl- 

 pool thus caused every animalcule within their influence; that in T. caput-serpentis the 

 cirri open and fold together somewhat like a butterfly-net. 



The shape assumed by the labial appendages is very different in some families and 



1 ' American Journal of Science and Arts,' 3rd series, vol. xvii, p. 257, March, 1879. 

 '* "Notes on the Brachiopoda oWrved in a Dredging Tour with Mr. McAndrew on the coast of 

 Norway," ' Ann. and Mag. of Nat. Hist.,' vol. xvi, '2nd scries, p. 257, October, 1855. 



