part 1] THROUGH THE ANDES OF PERU AM) BOLIVIA. 4<5 



what steeply into the cardinal fossula, which extends to the centre of the 

 corallum, and is penetrated by the counter- septum. 



Affinities. — This form appears to be closely related to Zaphrentis 

 disjuncta Carruthers, 1 the points of resemblance having- been noted above. 



LOPHOPHYLLOID CANINIA. (PI. I, figs. 7 «-7 C.) 



Description. — Corallum cylindro-conical ; variable in shape; often 

 showing- marked irregularities of growth. Epitheca thin and smooth, but 

 occasionally bearing traces of longitudinal ribbing. 



Horizontal sections. — Major septa irregular, with radial disposition; 

 slightly thickened at their inner ends ; Amplexoid in character from an early 

 stage, leaving a central tabulate area penetrated only by the counter-septum, 

 which is elongated and thickened to form a central columella!- plate. Cardinal 

 septum short. Fossula indistinct, usually bounded by the intersection of a 

 tabula with the plane of section. 



Minor septa absent or undeveloped. Tabulee few in number, somewhat 

 irregular and widely spaced. No marginal dissepimental zone. 



Affinities. — This form in its general septal development and irregularity 

 of growth appears to be more nearly related to Caninia than to the Za- 

 phrentids. It differs from Caninia cornucopise Michelin emend. Carruthers 

 (Geol. Mag-. 1908, p. 158) chiefly in the less numerous major septa, and by 

 the absence in all stages of growth of minor septa and an external zone of 

 dissepiments. In these respects it bears considerable resemblance to 

 Zaphrentis amplexoides Wilmore. 2 



Zaphrektis aff. erttca (M'Coy). (PI. I, fig. 5.) 



Description. — Corallum simple, conical, slightly cornute. Epitheca 

 strongly costate. Major septa, 22 in number, straight and slightly swollen 

 at their inner extremities ; radial in disposition and becoming Amplexoid at 

 an early stage of growth. 



Counter- septum long, extending more than half-way across the corallum ; 

 laterally thickened at its end to form a clavate columella. Cardinal fossula 

 inconspicuous, the break being indicated by a shortened septum. Tabular 

 intersections very regular and evenly spaced. Gaiter wall thick, but showing- 

 no trace of minor septa. No marginal zone of dissepiments. 



Affinities. — This form agrees closely with Cyathopsis eruca of M'Coy. 3 

 The genus ' Cyathopsis,' founded by A. d'Orbigny for corals resembling Atn- 

 plexus but possessing a septal fossula, is, however, an unsatisfactory one, and 

 the species was redescribed and figured as a Lophophyllum by Thomson & 

 Nicholson. 4 Mr. E.. G. Carruthers has shown that it can no longer be referred 

 to that genus ; and, until more light can be thrown on the phylogeny of 

 this and kindred species, it may be regarded as an Amplexoid Zaphrentis 

 possessing a Lophophylloid type of columella. 



In the possession of a strongly-costate epitheca, in the radiate arrangement 

 of the septa, and in the regularity of the tabular intersections, it shows a close 

 affinity with Cyathaxonia costata M'Coy, as figured by Vaughan 5 ; the latter 

 species, however, has now been assigned to the genus Lophophyllum by 

 Dr. A. Wilmore, r> although it appears to be doubtful whether that author is 

 justified in regarding the forms discovered by him in the Craven district as 

 identical with that figured by Vaughan, for the latter species is described as. 

 having a strongly-costate epitheca, and is apparently devoid of minor septa. 



1 Q. J. G. S. vol. lxvi (1910) p. 534 & pi. xxxvii. figs. 6a-8d. 

 " Ibid. pi. xxxviii, figs. 1-9. 



3 Ann. & Mag. Nat. Hist. ser. 2, vol. vii (1851) p. 167. 



4 Ibid. ser. 4, vol. xvii (1876) pi. viii, fig. la. 



5 Q. J. G. S. vol. lxii (1906) pi. xxix, fig. 5. 



6 Ibid. vol. lxvi (1910) p. 573. 



