O'CONNELL, REVISION OF THE GENUS ZAPHRENTIS 187 



The species Caninm gigantea Michelin, which Salee includes in his re- 

 vision of the gen-us'as~anrue Caninia, does not seem to fit in with the 

 typical Caninia {C. cornucopias) , inasmuch as its fossula is formed not by 

 the meeting of the septa and the abortion of the cardinal septum, but 

 rather by the down-bending of tlie successive tabulae to form a series of 

 invaginated funnels, upon which characteristic Scouler based his genus 

 Slphonophyllia, making C. gigantea Michelin the genotype. This down- 

 bending~of the tabulae forms not a true fossula, which is due to the abor- 



« tion of the cardinal septum (23, 48), but a peculiar type which may be 

 designated a "siphonofossula," and which may or may not be accompanied 

 by an abortion of the cardinal septum. Moreover, Caninia gigantea can- 

 not be included under Zaplirentis, as typified by Z. cornicula, although 

 Edwards and Haime considered it as such, changing the name to Z. 

 cylindrica in order to distinguish it from Lesueur's Canjophyllia gigantea, 

 which is commonly regarded as a typical Zaplirentis in the usual use of 

 the term. Thomson and Xicholson tentatively referred this species to 



/ CyathophgJhim, because it has the tabuUie restricted to the central area, 

 and has a well-marked circumferential zone of lenticular celis,^but still it 

 differs from CyathophyJJiuit in the possession of this pronounced and 

 unique siphonofossula. The name CyailiophyJhnn giganteiini was given 

 only temporarily until further restrictions should be made. With the 

 more precise definition of the genera, Caninia gigantea Michelin, cannot 

 be placed under either Caninia or Zaplirentis, but should be left as the 



^ type of the genus SiphonopliyUia which must be reinstated. Lesueur's 

 species of CaryophyUia gigantea was found in Kentucky and described 

 in 1820. This is the form commonly known as Zaplirentis gigantea 

 (Lesueur). That it cannot be placed in the same genus with Z. corni- 

 cula, the genotype of Zaplirentis, is evident, for it differs from the typical 

 Zaplirentis in having the tabular well developed, numerous, extending 

 entirely across the visceral chamber and bending down marginally. There 

 is no external vesicular zone, in which respect it agrees with true Za- 

 plirentis. On the other hand, the fossula is formed in the same manner as 

 in Siplionopliylli^ gigantea (Mich.) and is really a siphonofossula, the 

 cardinal septum being visible throughout the entire individual. Since 

 both Caninia gigantea and "Caryopliyllia" gigantea have this siphon- 

 like pseudofossula, and since both species are distinct and yet are generi- 

 cally misplaced, Scouler's genus SiphonopliyUia, which he originally based 

 on the former species as the genotype should be revived with that species 

 as type, while the name Siphonophrentis may be adopted for the other 

 species, CaryophyUia gigantea Lesueur being the genotype. 



