Report of the State Geologist, 



4W 



In Lingdla the pedicle is ;i \cry flexible, bighly muscular 

 body, often enormously developed in length. At its point of 

 emergence from the valves, it is exceedingly thick, abruptly 

 contracting from this point inward. It is composed of two 

 layers; an outer, thin corneous one, and an inner muscular one. 

 The organ is traversed for its entire length by a central canal 

 which is connected with the chamber inclosing the viscera (peri- 

 visceral cavity). The capsule, so highly developed in the tere- 

 bratuloids is here rudimentary, while the pedicle-muscle is well 

 developed. In Glot.iidia the pedicle has been shown by Morse to 

 he annulated, supplied with mural pores, and the central canal 

 to l>e tilled by a circulating sanguineous fluid. It has already 



Fig 108.— Leptoenarhomboidalis. A 

 very you ng shell, xlO. p, foramen; 

 /<s,^pediele-sheath. (Beechkr and 

 Clarke.) For the mature shell 

 see plate 13, figs 2, 3. 



Fig. 10'.).— Rafinesqvina 

 Ulrichi An adult 

 shell with the pedicle- 

 sheath highly devel- 

 oped. 



been observed that in Glottidia Audebardi the pedicle forms for 

 itself a covering of agglutinated sand grains, etc., being otherwise 

 unattached, and also possesses the power of contracting itself 

 violently in all directions. All of these characters are very 

 suggestive of relations to the Annelids, as has been forcibly 

 argued by the author quoted. 



Muscular System. 



The Brachiopoda which are articulated by teeth and sockets 

 can open and close their valves only in a vertical plane, and even 

 in this direction the capability of motion is very limited. They 

 also possess, to a limited degree, the power of protruding and 

 retracting the pedicle. We therefore find in the articulate 

 brachiopocls three sets of muscles, namely : Those which by 



51 



