Herbert L. Hawkins — On Lanieria of Duncan. 203 



inferieure toi:t k fait plane", ''pores ambulacraires . . . dans la 

 region inframarginale . . . simples et directement superposees ", are 

 features exactly corresponding with those of the three specimens 

 under consideration. 



In one of them (E. 11516) the sutures are well shown, and the 

 ambulacra are seen to consist of primaries from the apex to a point 

 very near to the peristome. The first sign of ' plate-crushing ' 

 appears at No. 89 from the apex, while in Lanieria the corresponding 

 point is about nine plates down. The diameter of this specimen is 

 18 -5 mm., and its height 12'25 mm., and the periproct is only 

 1 "4 ram. distant from the peristome. 



The other two specimens seem to agree closely in all visible 

 features with this one. No. E. 4574 is 18-5 mm. in diameter and 

 14-5 mm. high, while No. E. 11517 is smaller and less well-preserved. 

 The form appears to be new, and I select No. E. 11516 as the holotype. 

 The systematic summarj^ of the species can be expressed as follows : — 



CCENHOLECTTPTJS CTJB^, n.sp. 

 Syn. Echinoconus lanieri,va,T., Cotteau, 1881, Mem. See. g^ol. Belg., ix, p. 11. 

 Horizon : ? Uppermost Cretaceous, Cienf uegos, Cuba. 

 Type : e coll. A. H. Lanier, in British Museum. 



4. The family LAKIEEIINiE, NOV. 



As will be seen from the description, the characters of Lanieria 

 are anomalous and in some ways synthetic. The apical system and 

 tuberculation are definitely like those of CcenJiolectypus, while the 

 general proportions of the test, and particularly the stru,cture of the 

 ambulacra, conform more to the type of Conulus. The two latter 

 genera are strikingly different from each other, and are probably the 

 results of an early separation in phylogeny. It is therefore unlikely 

 that Lanieria, occurring in deposits of presumably Upper Cretaceous 

 age, can represent a truly intermediate stage between them. 



To my mind the characters of the apical system are less likely to 

 be suddenly or irregularly modified than those of the ambulacra. The 

 former structure is completely developed early in ontogeny, while the 

 ambulacra are continually growing (in the Holectypoida) throughout 

 life. It is therefore possible that some comparatively trifling change 

 could cause ' plate-crushing ' to appear in the ambulacra, whereas 

 fundamental and complete modification would be necessary for the 

 development of a fifth genital and gonad. 



It seems likely, therefore, that Lanieria is a peculiarly specialized 

 offshoot from the Discoidiidse, and has no direct phylogenetic con- 

 nexion with ConulUs. In a recent paper (Proc. Zool. Soc, 1912, 

 p. 450) T included Lanieria among the Holectypinse (by error as 

 a sub-genus of Rolectypus on p. 477), but liad not then seen a specimen. 

 In view of the remarkable ambulacral features, it seems best to place 

 it in a separate sub-family of the Discoidiidse, which may be called 

 the Lanieriinse. 



Another genus, Discholectypus, Pomel, which I regarded as " ineert<B 

 :" in the paper above referred to, can join Lanieria in this sub- 

 family. Discholectypus, whose type is Holectypus meslei, Cott., Peron, 



