DE. T. DAVIDSON ON EECENT BEACHIOPODA. 



225 



S. Morse is stated to liave found 

 shoal at 



Fis. 24. 



Glottidia 2>yramidata, from 

 life (after Morse). 



(Amer. Journ. Sci. and Arts, July 1870), Prof. E. 

 Glottidia {jnjramidata) Andel)arti "in a sand 

 low-water mark, buried just below the surface of the sand. 

 The peduncle was six times the length of the shell, and 

 was encased in a sand-tube, differing in no respect from the 

 sand-tubes of neighbouring annelids. In many instances the 

 peduncle was broken in sifting them from the sand, yet the injury 

 was quickly repaired, and another sand-case was formed. He 

 observed that the animal had the power of moving over tlie 

 sand by the sliding motion of the two valves, using at the same 

 time the fringes of setae, which swung promptly back and 

 forth like a galley of oars, leaving a peculiar track in the sand. 

 In the motion of the setoe he noticed tlie impulse commencing 

 from behind, and running forward. Within the mantle he 

 found a series of rows of prominent lamella?, in which the blood 

 rapidly circulated, thus confirming the correctness of Vogt's 

 observations. These lamellae were contractile, however. The 

 peduncle was hollow, and the blood could be seen coursing 

 through its channel. It was distinctly and regularly con- 

 stricted or ringed, and presented a remarkably worm-like appearance. It had layers of 

 circular and longitudinal muscular fibre, and coiled itself in numerous folds or unwound 

 at full length. It was contractile also, and would quickly jerk the body beneath the 

 sand. But the most startling observation in connection with this interesting animal was 

 the fact that its blood was red. This was strongly marked in the gills and various rami- 

 fications of the mantle and in the pedvincle. At times the peduncle would become con- 

 gested, and then a deep rose blush was markedly distinct." 



Prof. Owen states, in his observations on the anatomy oi Lingula Andebardli (p. 157), that 

 "the structure of this species corresponds in all essential particulars with tliat of Lingula 

 anatina as given by Cuvier. The differences appear first in the length of the cilia, Avhich 

 in the present species are three times longer than in Lingula anatina. The subdivisions 

 of the branchial vessels project from the inner surface of the mantle, in linear series similar 

 in tlieir direction to those of Lingula anatina ; but the lines are not continuous ; thev are 

 composed of distinct and separate folds of the mantle, of a minute size, along the con- 

 vexity of each of which a single vascular loop is extended without giving off lateral 

 ramulets, the whole structure affording a beautiful examj^le of the first stage in the com- 

 position of a complex lamellated gill. All the glandular masses communicating with the 

 alimentary canal bear the green colour characteristic of the liver, especially that central 

 one surrounding the stomach, which Cuvier has marked as the salivary gland of i. ana- 

 tina. "With respect to L. Audebardii, I shall only add, tliat the distal end of its pedicle 

 is dilated and rounded, and in the small specimen dissected did not present any appear- 

 ance of having been attached to a foreign substance Lingida, living more com- 

 monly near the surface, and sometimes where it would be left exposed by tlie retreating 

 tide were it not buried in the sand of the shore, must meet with a greater variety and 



30* 



