234 



sinus and separated by fissures. Hinge-teelh rudimentary or indistinct, never pro- 

 jecting freely in the aperture. Tlie supra-scapular chamber with a calcified roof. 

 The occlusion takes place in a similar way to that in Scuticella. 



Besides in the above mentioned characters the four species here described 

 correspond in the following. The scapular chamber is generally developed as a 

 small avicularium also on the adzocecial side of the daughter-zooecium, and the 

 first three lateral chambers form a *more or less compressed, protruding and 

 somewhat frontally directed, wholly or mostly calcified portion, which is separated 

 from the frontally directed pedal chamber by a rather large intermediate space. 

 There is a very small supra-scapular chamber on the adzocecial side of the 

 mother-zooecium and a pedal chamber on the adzocecial side of the daughter- 

 zooecium. The basal wall of the zooscia has a more or less distinct, longitudinal 

 striation. The gonozooccia, situated either on a mother-zooecium or on an inserted 

 zooecium, are always provided with at least two frontally directed lateral cham- 

 bers, which must be regarded as the scapular and the pedal. The frontal surface 

 of the covering kenozocecium has two large, transversely oval fenestrse, and within 

 each of these we find on the ooecium a long, dense collection of spinous pro- 

 cesses and tubercles, among which numerous pores are generally discovered. 

 Further a larger or smaller part of the frontal surface of the true ooecium is 

 provided with robust spinous processes, which have coalesced with the inner 

 surface of the kenozocecium. On the top of the latter we sometimes find a small 

 kenozocecium, sometimes a small avicularium communicating on either side with 

 a small calcified lateral chamber. 



Costicella solida n. sp. 



(PI. XX, fig. 7 a, PI. XII, flgs. 1 k, 1 h). 



The sternal area, which is not much longer than the aperture, has 5 — 6 

 fenestrse situated in a broad curve, within which a quadrangularly rounded cryp- 

 tocj'st lamina is seen. In the inner part of the area there are 5 — 7 very short 

 spines separated by distinct fissures, which show great variation in respect to 

 their mutual connection. The two distal ones are generally very high and plate- 

 shaped, and each of them has most frequently a larger or smaller, often bifur- 

 cate, inner cavity, which is connected with a pore in the middle of the oral 

 margin. In the others the inner cavity is usually wanting or if present extremely 

 narrow. 



The lateral chambers. The supra-scapular chamber has a triangular excision 

 on its frontal surface near the aperture and a smaller one in the outermost, 

 proximal part of the basal surface, while the infra-scapular and the pedal cham- 



