58 F- A. SMITT, 



able, as here also, in clead and dried specimens, to know anything about its physiolo- 

 gical significance. The ordinary zooecia have an oblong, rounded quadrangular aperture, 

 with a breadth of about 0,1 ram., 1 ) contracted in the middle, but very often this 

 breadth can be measured to about 0,is ram., and, sometimes, this also can be nearly 

 doubled, the form of the aperture, then, being more and tnore elliptical, transversely, 

 with pointed lateral ends. The proximal margin of this aperture is broadly concave, 

 with a little break at its ends, which gives the Myriozoidan eharacter to this species. 

 The front wall of the younger zooecia, usually, is a little convex and densely perfora- 

 ted by primary pores. As the calcification proeeeds, the surface of the whole colony 

 is levelled, the grooves between the zooecia being filled out, and their marginal pores 

 then, of course, are deeper and greater. These pores also, usually, are persisting, the 

 other being closed, and the front wall of the zooecia, at last, in the harder degrees of 

 calcification, being verrucose, in this respect very much resembling the Escharella Ja- 

 cotini. Distally of the aperture, where the decumbent, acute avicularia are placed, 

 converging with their tips, the calcification, usually, in a higher degree thickenes the 

 wall, this, without doubt, corresponding to the »penthouselike projeetion» at that place, 

 as described by Busk. The ooecia, as far as I can see, in this form are totally wan- 

 ting. The avicularia vary both to their size and number, in the typical state one at 

 each side of the zooecial aperture; but very often the one is wanting, the other then, 

 usually, being prolonged. This prolongation, especially, will affect the mandible, thus 

 actually producing a vibracnlum, whose developraent, otherwise, would be the most di- 

 stinctive eharacter of the following form; still, as far as can be seen on the specimens 

 examined, in this case the vibracularium here is single on each zooecion. 



E. setigera (fig. 206). 



Char.: Zooecia ovalia, convexa, imperforata, peripheriam totam marginis spissant 

 aperturse elongata?, fere elliptica?, in medio constricta?, vibraculariis ad latera aperturaj 

 positis rnuniuntur. Ocecia primo minute porösa stratu calcificationis imperforato e basi 

 accrescente obteguntur. 



Hab.: Coloniam hujus forma? fragmentum testa? mortuse investientem e prof. 60 

 orgyarum sustulit Pourtales. 



The two lateral vibracularia, with their vibracula of almost the same length as 

 the zooecia, and the uniform calcification of the convex, imperforated zooecial front- 

 wall, with the thickened margin of the aperture, whose breadth may be measured to 

 about 0,08 mm., readily will distinguish this form, which, furthermore, is provided with 

 ooecia. From this last circumstance one might infer, perhaps, it should hold any sex- 

 ual relation to the preceding form; but with our present knowledge of the Bryozoan 

 life, we have no right, at least, to such a supposition. The only specimen I have 

 seen, however, is very small and gives no further information on its developmental 

 changes. It was taken, like the preceding form, in the neighbourhood of Tortugas. 



') On the zooecia of a very young colony (fig. 203), I have measured this breadth to about 0,08 mm. 



