TRIBE II. CARYOPH YLLACEA. 359 



The Acervularise have a small cup-like cell, prominent within the 

 summit, and forming its centre, and are very proliferous from the 

 summits. The characters of the genus require more study before it 

 can be considered as established on sufficient grounds. 



This genus was instituted by Schweigger for the species figured 

 by Fougt in the Amaenitates Academic* (i., Corall. Bait., tab. 4, fig. 9, 

 and No. 2), .and thus- described by him: " Madrepora composita, cor- 

 poribus proliferis e centre pluribus, undique coadunatis; stella con- 

 vexa, centro concava." The genus is characterized as follows by 

 Schweigger (Handbuch, p. 418): " Stirps calcarea, e conis approxi- 

 mates : coni e cellulis lamellosis acervati omnes cellula terminali medio 

 protracta, e centro depresso prolifera ;" which may be translated : 

 " Calcareous and made up of approximate cones ; cones acervate and 

 proceeding from lamellate cells, which have a terminal cell at middle, 

 and are proliferous from this depressed centre." He names the 

 species A. baltica. The essential characters of Schweigger's genus 

 are retained in the above generic description. The convexity of the 

 summit exterior to the cup-like centre is not a universal character. 

 The Astrsea ananas, figured by Lonsdale (Sil. System, pi. 16, fig. 6), 

 belongs to this group as here characterized ; but his Acervularia 

 baltica, which differs from Schweigger's, is the type of another genus. 



The Strombodes of Schweigger may also fall in part into this genus. 

 The peculiar structure attributed to the species, the formation of 

 successive layers of cells, appears not to be of generic importance. 

 He thus characterizes the genus: "Stirps calcarea, e cellulis lamel- 

 losis in conos acervatis, strata horizontalia constituentes. Coni paralleli, 

 e cellula cyathiformi proliferi." (Handbuch, p. 418; see also Gold- 

 fuss, Petrefakten, 62, pi. 21.) The name is from gT^/Sos, a top, and 

 refers to the peculiar structure above alluded to. Blainvilte changes 

 the name to Strombastreea (Man. d'Actin. p. 376). The Strombodes 

 of Ehrenberg includes those solitary Cyathophylla of Goldfuss, which 

 from their peculiar interrupted mode of growth appear to consist of a 

 series of inverted cones ("tanquam conis e centro proliferis"). These 

 species, " Ringel-Coralle," pass so gradually into others with a nearly 

 smooth exterior, that the character can hardly be considered as of 

 sufficient importance for founding a genus. The same principle 

 carried out would require a subdivision of the genus Cystiophyllum. 

 Ehrenberg includes in his genus a recent species from the Red Sea, 

 which is referred to under Euphyllia. 



Lonsdale and Phillips apply the name to species which have the 



