PEROPHORA ANNECTENS. 6l 



diary bands " {m. i. h. and o. i. b.) of Fol, and the cells 

 carrying the long cilia at the bottom of the furrow 

 (;;/. c. c.) 



Both the intermediary bands are ciliated, though the cilia 

 are quite different in the two cases, those of the outer band 

 being considerably shorter and more spike-like than those 

 of the middle band {vd. figure) . Likewise, there is quite a 

 marked difference between the cells of the two bands, as the 

 figure shows. Those of the middle band form but a single 

 layer, and are cuboid, with round nuclei; while those of 

 the outer band are two or three deep, and are consider- 

 ably elongated, and contain spindle-shaped nuclei. And 

 further, the latter stain much more deeply than the former. 

 In this respect they resemble the cells of the middle cili- 

 ated band, ;;/. c. c, much more closely than those of the 

 inner ciliated band. The middle band is, however, but 

 one cell deep, these cells being very long funnel-shaped. 

 Their broad ends are directed inward, and bear the ex- 

 tremely long cilia so characteristic of the tunicate endos- 

 tyle. The distinctness with which these cells are stained 

 by acetic acid carmine, as compared with those of the 

 glandular pads on either side of them, renders them very 

 striking in the sections. The glandular pads (/. g. c, 

 m. g. c. and o. g. c.) are usually considerably thicker in 

 proportion to their width than in the section here figured, 

 this being caused by the cells being longer, not by the 

 pads being more than one cell deep. 



d. THE SUB-NEURAL GLAND. 



The duct, particularly the opening of it, differs some- 

 what from that of P. Listeri, as described and figured by 

 Garstang ('91, p. 60, and fig. 5). 



As seen by fig. 21, pi. ii, d. t., and as already men- 

 tioned in the diagnosis, the opening is not in the median 



