416 Dr. W. C. M^Intosli on Pelonaia corriigata. 



longitudinally and crossed by regular transverse bands^ on the 

 •whole somewhat resembling the same apparatus in BoUenia^'. 

 Under a power of 90 diam. (fig. 5), the longitudinal fibrous 

 bands («) are crossed by circular belts [b] of nearly equal thick- 

 ness, and the square or oblong spaces thus formed are again 

 subdivided by more slender bands (c). All these bands project 

 inwards from the ovoid branchial spaces; and thus, when viewed 

 from the inner surface, the latter are in the background, as in 

 the figure. A portion of the branchial membrane, somewhat com- 

 pressed, and with the small circular band (c) removed, is repre- 

 sented from the spirit preparation in fig. 6, x 200 diameters. The 

 aperture is surrounded by a well-defined minutely granular rim 

 of cells, which cells in life are covered with long and powerful cilia, 

 whose remains are apparent even in the spirit preparation. The 

 branchial fenestrated membrane is continued along the stalk of 

 the animal to the oral aperture (c^, fig. 2). This oral aperture, 

 when removed from the test, is found to be situated in the largest 

 and most muscular of the terminal cones; and when this is con- 

 tracted, a little within the opening are a number of small red 

 specks. Below these is a ring of minute filiform tentacles (fig.3), 

 composed of a transparent basement structure, with numerous 

 granules. 



The termination of the slendei; end in the larger example as 

 seen under a lens is shown in fig. 7 ; and it had a less sandy invest- 

 ment than the rest of the animal : indeed towards the end the 

 sand-particles obtained an individuality not seen elsewhere, from 

 the predominance of the tough basis substance. In the smaller 

 specimen this part was similar to the rest in this respect. The 

 oral aperture is seen at a, and the anal at b. Each of these 

 apertures had a concentric and finished arrangement of carun- 

 culse and papillae externally. The external investment of the 

 narrowed portion is the densest on the animal, though, as above 

 mentioned, the sand-particles are less closely set towards the 

 tip. The glistening white fibrous lining of the test is also 

 thickened; it becomes more yielding where it expands to meet 

 the bulbous portion. The muscular layer of this part formed a 

 powerful tube (/, fig. 2) of external circular and internal longi- 

 tudinal fibres. 



The endostyle lies along the side of the branchial chamber 

 (^, fig. 2), and forms a somewhat zigzag pinkish band. A por- 

 tion from the larger specimen is seen in fig. 9, viewed under a 

 lens. This structure looks like a simple folded basement mem- 

 brane, with a closely set series of granular cylindrical epithe- 



* Saviguy, * Memoires sur Ics Aniniaux sans Vert.' 2ii(l part, V fascic. 

 ] 1. 6. I am indebted to Dr. Lauder Lindsay for kindly plaeing a speciuien 

 of Boltenia from Otago, New Zealand, at my disposal. 



