34 F. A. SMITT, 



species of Lunulites, described by Busk l ), from the Philippine Islands, at least to the 

 Lunulites cancellata; bus as he has had only worn specimens, it is impossible to say 

 anything of their true apertural form. The other species of Lunulites, cited by him, 

 belong to the Flustrine group. 



The Mamillopora cupula is taken by Pourtales at seven different localities in 

 the Floridan sea, in very good and complete specimens, varying, as to the shape of 

 the colony, in accordance with our figures 147, a — c. Yet all the vibracularia (?) want 

 their operculum (vibraculum), so that it is impossible to say, wliether they are, in 

 reality, vibracularia or avicularia. In sorne of the specimens, they hold a tolerably 

 regular position in linear rows between the zooecial rows, just as remarked by Busk 

 (1. c.) in the character of Lunulites; but in other colonies they are very irregular in 

 their development. Their aperture is elliptical, with the same constriction at the ar- 

 ticulation of the vibraculum (?), as that in the aperture of the zooecia at the articu- 

 lation of the operculum. At the back side of the colony they are still more irregu- 

 larly spread but hold the same size and form. The cancellation at this side of the 

 colony, where it is developed, lies only as a thin layer of bladders (abortive vibracu- 

 laria?) on the back of the zocecia. 



As to the form of the zooecia, they agree pretty well with the description of 

 Lunulites cancellata given by Busk, which description seems to have been founded on 

 highly calcified, dead and worn, young specimens; but for the circular apertures, together 

 with the greater development of the cancellation on the back side of the colony, on 

 the Philippine form, I dåre not to conjoin these two forms into one species. In the 

 ' Mamillopora cupula, the elliptical zooecial apertures 2 ) are constricted at the articulation 

 of the operculum, whereby, as the proximal margin is broadly sinuated, a rounded 

 sinus is formed, also, on each side, between the named constriction and sinuation. 

 Thus, the apertures have a very characteristical shape; but it is not easy to discern, 

 bi-cause, when the operculum and the covering corneous membrane of the proximal 

 part of the aperture are retained, these make its margin obscure, and in the worn 

 specimens the named character, also, very easily is evanished. As the apertures occupy 

 nearly whole the front of the zooecia, with their incrassated margin they are placed 

 very near each other in the radiating rows. In the margin, sometimes I have seen 

 rounded holes, looking as they were marks after decayed spines; but more usually the 

 incrassation of the margin goes on irregularly, in forming rounded tubercles, without 

 any marks of true spines. 



The ooecia are more or less swollen. When found on the margin of the colony, 

 they are almost spherical. Their front side is densely prickled by pores and usually, 

 by a longitudinal impression, divided into two tumidnesses. It is very common to find 

 them attached to zooecia with a greater aperture than the ordinary ones 3 ). 



1 ) Got. Polyz. Brit. Mus., p. 101. 



2 ) I have ineasured the length of t lie aperture of the ordinan' zooecia (without ooecia) varying between 0,J6 

 and 0,19 mm. 



• ! ) Whether these ooecia, as to their physiological funetion, are to distinguish from those, "which are attached to 

 zooecia of ordinary construetion, in died and dried specimens, of course, it is impossible to decide 



