348 



of (respectively ca. 4—6 and 3—4) small, uniporous rosette-plates. The colonies 

 are incrusting and superficial budding occurs in most. 



Whilst spines never occur in any member of the family Celleporidae, such are 

 found on the other hand in a number of species of this family to a number of 

 2—6, e. g. in ^Cellepora<^ apiculata Busk, C. tridenticulata Busk, Cellepora brunnea 

 Hincks, C. verrucosa Mac Gill., C. bicirrhata Ortm., C. triacantha Ortm.^ and yDis- 

 coporai^ advena Smitt. The aperture has a concave or straight proximal margin, 

 and though this in very rare cases may have a slight, rounded incision centrally, 

 it cannot be compared with the sinus in Cellepora. This sinus is in reality the 

 interspace between the two hinge-teeth or the two corresponding places of sus- 

 pension for the operculum, whereas in the species mentioned as in all the other 

 species of the family Holoporellidae, the hinge-teeth or the corresponding places 

 of suspension for the operculum are situated on the lateral margins, which are 

 well-separated from the proximal margin. Another difference lies in this, that this 

 excision is not as the sinus in Celleporidae occupied by an opercular tongue. Such 

 a small, rounded incision is found for instance in ^Schizoporella' aperta Hincks, 

 which belongs in reality to this family. In not a few species the proximal margin 

 of the aperture is provided with a row of 3 — 6 teeth of varying form but usu- 

 ally high or narrow, all of which are situated outside the operculum, so that 

 none of them can be compared with hinge-teeth. Such teeth, which presumably 

 serve to protect the operculum, are found in C. tuberculata Busk, C. honolulensis 

 Busk, C. Jacksoniensis Busk, C. tridenticulata Busk, C. polymorpha Busk, C. serrati- 

 rostris Mac Gill. ^, C. bicirrhata Ortm. ^, C. transversa Ortm. ^ and " Discoporai- ad- 

 vena Smitt. 



The ooecia, which occupy the greater part of the margin of the aperture, are 

 widely open, have no pores and consist only of a single calcareous layer, which 

 seems to lack a covering membrane; but as the ooecia-bearing species I have 

 been able to examine were almost all dry specimens, I cannot determine this 

 question with certainty. If a covering membrane is really lacking, they must pro- 

 bably be regarded as peristomial, but in any case they are very different from 

 the ooecia in the Celleporidae. Good drawings of such ooecia are seen in Hincks' 

 figures of ■^SchizoporellQ'i aperta^ and ■> Monoporellai albicans^ and in Waters^ 

 figure of Holop. Descostilsi Aud. Superficial budding occurs in this family just as 

 in the family Celleporidae, and the rosette-plates therefore only occur in the 

 basal zooecial layer. The zooecia in this family in contrast to the foregoing have 

 a rectangular circumference, and both the distal wall and the distal half of each 



• 68, p. 114. ^ 87, p. 55. ^ 26, p. 126. * 26, p. 123. ' 116 a, p. 162. 



