62 F. A. SMITT, 



the younger zooecia, especially around the pores, has a milky appearance. Still, the co- 

 lour of a more outgrown colony is yellow, as also in Gemellipora striatula. 



The most characteristical difference between these species, which has caused u.s 

 to place them in different families, depends on the shape of the zooecial aperture, 

 which here, in the Lepralia inomata, is keyhole-shaped by the contraction at the ar- 

 ticulation of the operculura, usually at the third part of its length. Thus, indeed, in 

 the comparison with the preceding family, • it most nearly approaches to the form of 

 the Escharella depressa or to the above described structure of the Myiiozoum ovurn, as 

 being constituted by a combination of fr\vo circles of unequal size ; but this resemblance, 

 readiest to be accounted for as a consequence of its low position in the serial deve- 

 lopment of the escharine type, is far exceeded by its agreement with the Lepralia 

 cleidostoma, so as nearly to be impossible to distingnish from it. 



From the PorjRTALES-collections to judge, the Lepralia inomata, at first described 

 as a fossil from the Eocene formation, seems not to be common in the Floridan sea, 

 as I only have seen two colonies, growing on dead shells, the one from 26, the other 

 from 60 fathoms. 



Lepralia cleidostoma (Pl. XI, figs. 217 — 219). 



Char.: Zooecia rhombica, primo ventricosa, calcificatione progrediente deinde con- 

 fiuentia, aperturam (cujus låtit. = 0,1 — 0,13 mm.) prsebent claviformem, ad tertiam par- 

 tem longitudinis coarctatam (juvenem setis marginalibus 2 1. 3 interdum fimbriatam); 

 aviculariis lateralibus acutis, extus vergentibus muniuntur. Ooecia globosa striis radian- 

 tibus ornantur. 



Hab.: Lepralice (auctt.) et Celleporce (auctt.) formam, Coraliis et testis insidentem, 

 e proff. 30 — 120 orgyarum hane speciem sustulit Pourtales. 



With the same shape of the zooecial aperture, as in the preceding species, differ- 

 ing only in size, the Lepralia cleidostoma, through its zooecial form and strong calci- 

 fication, combines the general structure of the aretie L,epralia hippopus '). Its distinc- 

 tive characters, in comparison with that species, Avould be the narrowness of the prox- 

 imal part of the zooecial aperture, the wanting of the pores in the zooecial wall, the 

 acute form of the avicularia and the striation of the ocecia. But all these characters, 

 from systematical point of view, if justly reviewed, will loss the greatest part of their 

 weight. The proximal rounding of the zooecial aperture, here, as being partly filled 

 up, can get the proximal margin less concave, more approaching to the corresponding 

 structure in the Lepr. hippopus; and, in that species, we have remarked 2 ) a secondary 

 change approaching the form of the Lepr- cleidostoma. As to the pores in the zooecial 

 wall, their wanting, as in many other instances, can be accounted for by the very 

 common variability of the calcification. That same variability, in one and the same 

 colony, in other species, has been found to be the case with the form of the avicula- 



J ) Öfvers. Vet. Akad. Förh. 1867, Bih., pgs. 20 and 127. 

 2 ) I. c, p. 128. 



