221 



portion (the adzooecial side of the mother-zooecium M'ithout an avi- 



cularium). Calpidium Busk. 



1) No inner calcareous lamina within the frontal wall: 



7) The lateral chambers occupying only a small part of the surface 

 of the zocecium; no longitudinal ridges dividing the frontal surface of 

 the zocecium into two lateral halves: 



8) The frontal surface with a circle of small round fenestrje, and 

 the zocecium with a wing-like, protruding marginal portion on each side 

 in the whole of its length; this marginal portion formed only by the 

 supra-scapular and the scapular chambers, the latter of which is devel- 

 oped into an avicularium; hinge-teeth slightly developed and not 

 protruding into the aperture; the latter furnished with a well devel- 

 oped sinus Hincksiella n. g. 



8) The frontal surface furnished at most with extremely fine, scat- 

 tered pores; no wing-like marginal expansions; the pedal lateral cham- 

 ber very oblong, narrow, sometimes linear; hinge-teeth strongly devel- 

 oped, freely protruding into the opening; the latter has a concave 

 proximal somewhat protruding margin; the aperture is ultimately 

 closed by three calcareous processes issuing from the inner margin 



and meeting in the centre Catenaria Savigny. 



(Vittaticella Maplest.). 



7) The lateral chambers occupying nearly the entire surface of the 

 zocecium and on the frontal surface only separated by a narrow, 

 longitudinal ridge, divided into two by a furrow; this ridge has an 

 annular expansion, perforated by a pore, on the proximal side of the 

 aperture Strophipora Mac Gillivray. 



Scuticella n. g. 

 (Catenicella auct.) 



The sternal area has 3 — 14 (in a single species only one) fenestrae or pores, 

 disposed in a curve or an angle, and on its inner surface a rounded calcareous 

 lamina springing from the proximal margin of the aperture. The hinge-teeth are 

 rudimentary or indistinct and never freely protruding into the aperture, the 

 proximal margin of which may be straight, concave or convex, sometimes with 

 a small sinus or indentation, to which however the operculum never corresponds. 

 The lateral chambers are wholly or mostly membranous, and the adzooecial, sca- 

 pular chamber of the daughter-zooecium is never developed into an avicularium. 

 In the old zooecia the aperture is not only closed by a calcareous lamina spring- 



