234 BULLETIX: MUSEUM OF COMPARATIVE ZOoLOGY. 



alone examined the former, pointed out, at the same time, that it pos- 

 sessed a much larger prominence on the "dorsal edge" (posterior part) 

 of the body than did Moseley's individual In this particular the 

 "Albatross" specimens agree with the one studied by Herdman, and 

 differ strikingly from the well-known figure of the type drawn by 

 Moseley. 



Of the five specimens in this collection, kindly entrusted to me by 

 Mr. Agassiz, three are in exceptionally good condition ; the fourth is 

 badly mutilated, parts of it being wanting ; while the fifth is so frag- 

 mentary as to be of little value. In fact it is possible that the parts 

 which I have considered as constituting the fourth and fifth all belong 

 to one ; so that in reality there may be only four individuals. 



As to general characteristics of the oral disc and rays, my observations 

 agree so nearly with what we already know of the animal from ]\roseley 

 and Herdman that it would be superfluous to go over the ground in detail. 

 Comparison of my figures with the figures by these authors will reveal 

 at a glance the slight differences I have noticed. Probably the most 

 important of these is in the relative size of the rays. There is, I think, 

 rather more difference in both length and width between the two 

 anterior, and the two posterior mys in all the " Albatross " specimens, 

 than either Moseley's or Herdman's figures indicate. In the largest 

 individual the anterior rays measure 4 cm. in length, while the posterior 

 are 3 cm. Again, I do not find the tips of the rays to agree quite with 

 the published figures. They taper more gradually and terminate in 

 sharper points than Moseley and Herdman have shown ; and Moseley 

 speaks of the rays as terminating in " abruptly narrowed tentacle-like 

 tips." This, however, is probably merely a matter of preservation. The 

 "Albatross" material is preserved in rather strong formalin, and this is 

 a much better preservative tlian alcohol for all tunicates, at least so 

 far «8 the conserving of general form and color is concerned. This 

 makes it worth while to remark that no pigment has been observed 

 in any part of these specimens excepting a very faint yellow mark along 

 the peripharyngeal band, the deep orange-red of the sense organ, the 

 light yellow of the gonads, and the brown of the intestine. As the 

 material came under my observation within eight months after its 

 preservation, it is quite certain that the animal is almost entirely 

 colorless. 



In one individual the whole ** nucleus " is everted through the 

 branchial orifice and lies on the oral disc. This condition has enabled 

 me to make out se\^ral points that would probably have escaped notice 



