248 J. H. ASHWOETH. 



7 mm. long, and I'O mm, to 1*2 mm. broad. Tentacles 2 ram. 

 to 5-7 mm. long, and '75 mm. broad. The total length of the 

 adult polyps is thus 6 mm. to 12 mm. 



The body of the polyp is cylindrical and its wall moderately 

 strong. In several of the Xeniidee the body-wall of the polyp 

 is so weak that when the colony is taken out of spirit the polyps 

 fall together into a mass. In this species, however, the body- 

 wall is just strong enough to support the polyps in an upright 

 position, so that on removing the colony from spirit the polyps 

 do not hang limply, but remain standing approximately in their 

 natural positions. 



Tentacles and Pinnules (PI. 24, figs. 2 and 3).— Each 

 polyp bears eight tentacles, each of which is provided with 

 numerous pinnules. The pinnules on each side of the middle 

 line of the tentacle are arranged in three longitudinal rows, 

 and they form also somewhat oblique transverse rows of three 

 pinnules rising from the oral towards the aboral side of the 

 tentacle (fig. 3, D). When the tentacle is viewed from the 

 inner or oral aspect, all the pinnules are generally visible 

 (fig. 3, B, D), but on the outer or aboral side of the tentacle 

 only the outer longitudinal row of each side is, as a rule, 

 seen (fig. 3, A, C). The pinnules are often clearly separated 

 into the two series of three rows in each by a narrow area 

 which extends along the middle line of the inner face of the 

 tentacle, from the base to within a short distance of the tip 

 (fig. 3, D). This area, free from pinnules, may be "25 mm. 

 across, and may often be traced to within 1 mm. of the tip of 

 the tentacle. In other specimens, however, it is entirely 

 obliterated, and the median pinnules of the two series are in 

 contact with each other, at any rate at their bases. The 

 width of this area varies, not only in separate individuals, 

 but in the different tentacles of the same individual. These 

 variations are probably due to the different degrees of con- 

 traction of the tentacles on killing, and the condition in which 

 the free area is well marked is seen only in those tentacles 

 which have been killed in an expanded condition. 



At the tip of the tentacle the pinnules are smaller than those 



