BIGELOW: THE CTENOPHORES. 375 



Four more Pleurobrachias must still be considered: — - globosa 

 Moser, pigmentata Moser, striata Moser, and crinita Moser. The 

 original specimens of globosa were all very small (1-6 mm. high), 

 and immature. Slightly larger examples, up to 8 mm., have been 

 described by Browne ( : 05) as globosa var. ceylonensis. The only 

 important difference between them and Moser's material was that 

 the ribs were somewhat longer; but this difference was evidently a 

 concomitant of growth; in fact just what is to be seen in pileus. 

 Moser mentions as its distinctive features: — -very short ribs, long 

 funnel-tube, opening of the sheaths on a level with the aboral ends of 

 the ribs, and the fact that the adradial canals open into the meri- 

 dionals in the oral | of the latter, i. e. slightly above the level of the 

 funnel. All but the last of these characters are shared with the young 

 bachei in the present collection. But in the latter the adradial canals 

 join the meridionals above the middle of the latter, just as they do in 

 pileus. 



It is unfortunate that we do not know what changes, if any, globosa 

 undergoes with advancing growth; at present it is impossible to de- 

 termine its status definitely. But the difference between it and all 

 the other Pleurobrachias yet described is so striking that it must be 

 recognized as a distinct species, at least provisionally. It is to be 

 hoped that its adult will soon be discovered. 



Pleurobrachia pigmentata and P. striata are very easily distinguished 

 from all other Pleurobrachias by the pigmentation of the paddle-plates. 

 In general appearance they suggest Tinerfe, but, unlike that genus, 

 all the meridional canals develop sexual products. The differences 

 between pigmentata and striata are that the latter is more nearly 

 cylindrical than the former and has a larger mouth, the fact that 

 its ribs are unequally spaced, slightly shorter and narrower, and that 

 the cilia are larger. But these are just the characters which are most 

 readily altered by preservation; I have seen the differences in form, 

 in the mouth, and in the cilia outlined above appear after preservation 

 in a series of pileus which I had previously examined and found in- 

 distinguishable in life, and that, too, when all were put into the same 

 bottle of formalin. The spacing of the ribs may be of more importance 

 but in shrivelled pileus the spacing often becomes unequal. I there- 

 fore doubt whether striata is distinguishable from pigmentata. P. 

 crinita is separated from its relatives by "die konische Gestalt, die 

 grosse Lange dei Rippen und Schwimmplattchen und durch die 

 Form des Mundes, der in vier Zipfeln von hornartig gekriimmter 

 Gestalt ausgezogen ist " (Moser, : 09, p. 148). These features are not 



