3"0 EDWARD S. MORSE ON 



vesicle (59: 4, 7). Under various pressures, no fluid, or other contents could be forced out 



at its point of attachment with the genital baud, nor was any opening or duct found 



upon its surface. There was a slight glandular thickening on the edge of the genital band 



(59: 8), and a similar thickening was fouud on the posterior edge of the ilio-parietal band, 



as shown in 56: 2. In T. coreanica, the edge of the ilio-parietal band is not only 



thickened, but it has the reddish-yellow coloration that we have seen associated with the 



spermaries, and which also tinges the vesicle in those forms studied. This colored 



glandular thickening of the edge apparently runs from the central vesicle to the accessory 



vesicle without a break. In 39: 12, this feature is shown in color. The central vesicle 



resting on the posterior dorsal surface of the stomach was bluntly triangular in shape, 



with the base anterior, and the sides of the triangle strongly lobulated. From the 



median line in front, the band, which Hancock mistook for an artery, divides and 



passes forward and downward on the sides of the stomach and then, laterally, making 



three short flexures, turns abruptly backward to terminate in the accessory vesicles. It 



may be observed that these flexures are the result of the loose folding of the ilio-parietal 



band and this so-called artery arises from the edge of it. It will be oljserved that this 



structure, from the central to the lateral vesicles, is distinctly tinged a reddish-yellow and, 



as before observed, it is the color which tips the filiform spermaries and other parts of the 



genital apparatus already described, but I have not observed this color associated Avith the 



eggs in Terebratulina, though the purple ovarian leaflets in T. coreanica were tipped 



with it. It is a very significant fact that no blood vessel, sinus, or lacune shows a trace of 



this color. In another specimen of T. coreanica, the central vesicle was oblong and was 



thrown into a series of folds or plications (59: 10, ll). The folds were slightly darker in 



color. With transmitted light, no cavity was detected within, and it seemed to be made 



up of irregular masses of radiating tissue which appeared glandular. No channel could be 



detected at its point of attachment, nor was a trace of muscle fibers discerned. The 



lateral or accessory vesicles (59: 12, 13), seem to have the same structure without folds or 



plications. The exterior surface of the accessory vesicles was granulated with minute 



cells, with a yellowish substance interspersed. 



Precisely what role these various parts play in the organization of the animal, I have 

 not made out, but that they are intimately related to the genitalia, there can be no doubt. 

 It may be added here that while the nephridia, as well as many other parts of the 

 anatomy, in all species examined, reveal the presence of ramifying lacunae through 

 which the blood is seen rapidly circulating, these vesicles, central and accessory, are about 

 the only organs which show no trace of any circulating fluid within or without. 



