'6bb EDWARD S. MORSE ON 



In T. coreanica (57 : 11) the pallial membrane has a strong reddish-salmon color 

 derived from the color of the shell. The main sinus in the dorsal palUum runs parallel to 

 the outer lateral border of the shell and nearly midway between the outer border and the 

 median line. It sends out twelve lacunae which subdivide once or twice before reaching 

 the border of the pallium. The ventral pallium sends two sinuses running irregularly 

 forward, the inner one, near the median line, sending its branches to the anterior border, 

 the outer sinus covering the remaining surface of the pallium with a less number of 

 branching lacunae. The two sinuses are connected with a single lacune near their origin. 

 The terminal lacunae are shown in 57 : 11a, and in these may be seen the middle ridges of 

 ciliated epithelium. The sinuses and lacunae, when filled with eggs, are dark purple in 

 color, as shown in 39: 14. The sinuses and lacunae in T. transversa seem to have the 

 same disposition in the pallium as in T. coreanica. 



In closing the description of the pallium I must again emphasize the fact that not 

 only the sinuses and lacunae of the pallium support the ciliary ridges which divide and 

 subdivide with the ramifications of the lacunae, but the minute lacunae in the nephro- 

 stome of Lingula, the papillary prominences in the nephrostome of Terebratulina, and 

 these channels wherever seen, present the same ciliary ridges. So far as I have 

 observed, the circulation of the blood is due to ciliary action and to the agency of this 

 action alone ; as in other groups, however, the contraction of the body must cause volumes 

 of blood to surge back and forth.^ 



Blood Corpuscles. 



In the blood of Glottidia (54 : 3) , are seen three kinds of corpuscles. These consist 

 first : of long, oval, and fusiform bodies ranging from simple oval bodies with pointed ends 

 to elongate forms with one or two swellings, and in a few cases showing a bifurcation at 

 one end ; these are amoeboid and bend and turn in rounding the corners of a lacune or in 

 crowding through some narrow opening; second: small, rounded corpuscles with a 

 constriction in the centre resembhng in appearance a partially collapsed rubber ball ; these 

 are nearly uniform in size and are much smaller ; third : round or oval bodies showing 

 a slightly granulated structure and varying greatly in size; these are probably ova. 

 The blood is rosy in color and causes the rosy hue of the paUium and peduncle. In L. 

 lepidula (54: 4) the corpuscles resemble very closely those found in Glottidia; the 



1 In 1861, Macdonald, in the Transactions of the Linnean society ('61) announced the discovery "of a determinate circu- 

 lation of spherical, and violet tinted corpuscles in all the ramifications of the pallial sinuses, not dependent on the contractions 

 of the pallial cavity, but upon the undulations of a ciliary lining." This paper of Maodonald's has been singularly overlooked 

 by English and continental workers on the subject. 



