282 University of California Publications in Zoology. [Vol.4 



surrounded by a definite border, the upper or distal portion of 

 which sometimes dips inward slightly, making it very obscurely 

 lunate. The space within the border is completely filled with an 

 oval plate in which are several minute pores, the plate being in 

 reality a sieve (fig'. 34). The shape and structure of this median 

 pore are thus very different from that of ill. ciliata, and its pe- 

 culiar features are constant in the specimens examined and are 

 considered sufficient to constitute a species as Busk first described. 

 Typical 31. ciliata does not occur in this collection. 



M. calif ornica is quite abundant, having been found at numer- 

 ous points on the coast of southern California especially, gener- 

 ally in conjunction with Scliizoporella liyalina. 



51. Microporella malusi (Audouin) Hincks. 



PI. 18, figs. 35, 36. 



Cellepora Malusii Audouin and Savigny, 1811, p. 239, pi. 8, fig. 8. 



Lepralia Malusii, Johnston, 1847, ed. 2, p. 314, pi. 55, fig. 4\ 



Heptoporina Mahisii, d'Orbigny, 1850-52, p. 443. 



Lepralia Malusii, Busk, 1854, pt. 2, p. 83, pi. 103, fig. 1-4. 



Lepralia Malusii, Busk, 1859, p. 53, pi. 8, fig. 3. 



Lepralia Malusii, Waters, 1879, vol. 3, p. 33. 



Microporella Malusii, Hincks, 1880, p. 211, pi. 28, figs. 9-11; pi. 



29, figs. 1, 2. 

 Microporella Malusii, Busk, 1884, pi. 30, vol. 10, p. 137. 

 Fenestrulina Malusii, Jullien, 1888, p. 38, pi. 15, figs. 1-3. 



Zoaria forming circular patches incrusting old stems, rocks, 

 etc. Zocecia irregularly ovate or rhomboidal, alternate, radiating 

 from a central point; front wall calcareous, punctate, slightly 

 convex, margins well defined (fig. 35) ; immediately inside the 

 margin a row of stellate pores ; the center of the front wall occu- 

 pied by a large semi-circular pore whose edges are irregularly 

 toothed. Orifice straight below, semi-circular above, with four 

 or five marginal spines ; spines prominent on the marginal zocecia 

 and present, though frequently broken, on the margin of inter- 

 mediate zocecia. Oa'cia globose, partially covering the lunate 

 pore of the zooecium next above, and surrounded by an areolated 

 border. The primary zooecium (fig. 36), that from which the 

 colony originates, is circular in form, its margin surrounded by 

 ten flaring spines. 



