G BULLETIN OF THE 



mouth, in front of the supra-oesophageal body. A striking feature in its 

 anatomy, which I believe has not yet been noted in any publication on 

 Brachiopods, is the absence of that great series of sinuses in the ante- 

 rior part of mantle, 'which was termed by Hancock the "great pallial 

 sinuses." So extraordinary did this appear to me, that I could not be- 

 lieve, at first, that I was not deceived by the translucency of the mem- 

 branes, and it was only after an examination of many specimens that I be- 

 came convinced that they did not exist in this species. There is in the 

 free lobes of the mantle an extensive and extremely close and fine network 

 of minute channels ; or perhaps it might be said that the whole of the 

 mantle lobes form one great lacune, the upper and lower walls of which are 

 held apart by a profuse number of pillars of tissue, which appear like dark 

 spots under the microscope, and which are situated so close together that 

 the spaces about them are reduced to minute channels. This system occu- 

 pies the anterior lobes of the mantle, which in some species also contain large 

 branching sinuses, here absent. On the outer surface of the perivisceral 

 chamber, above and below, on each side of the attachments of the principal 

 muscles, a small system of sinuses exists, and here are situated the genitalia 

 which necessarily assume a reticulated aspect quite different from the loops 

 and branches seen in Waldheimia and Terebratella. In the inner lining of 

 the mantle are scattered, everywhere, delicate branching spiculae, looking 

 like briers more than like deer-horns, and, while more or less interlocked, 

 and here and there stout and thick, are still much more delicate and slen- 

 der than those of Tcrebratidina caput-serpeiitis and Megerlia truncata, and 

 do not often exhibit a stellar arrangement. They are much more numer- 

 ous in some individuals than in others, and when present in abundance are 

 found in almost every part of the epithelium, even to the brachial cirrhi, 

 where the spicules are slender and not branched. They are especially 

 numerous over the perivisceral chamber and in the supra-cesophageal tissue. 

 The oral aperture presents no special peculiarities. The oesophagus is 

 wide and funnel-shaped, narrowest at its junction with the stomach, which 

 it enters at an acute angle. The stomach is small and oval, tapering to- 

 ward the intestine, which is nearly twice as long as the oesophagus. In the 

 stomach was a dark mass of calcareous granules, fragments of Foraminifera, 

 etc., filling it quite full ; among the debris was, in one specimen, the re- 

 mains of a small red crustacean with a large carapax and ( ? six) legs, 

 somewhat resembling a young Limulus, but much smaller. Other unrecog- 

 nizable crustacean fragments were noticed in other cases. Notwith- 

 standing the crowded state of the stomach, the intestine was always 

 empty. Its caecal end was somewhat blunt and rounded, and several fold- 

 like thickenings of the mesentery recalled Hancock's figures of the termi- 

 nation of the intestine in W. cranium. The pointed lower ends of the 



