1920 PARKINS0N1DM 29 



times peripheral tubercles bordering the sulcus are well shown in inner 

 whorls. 



Genera, Parkinsonia, (Choffatia P) Strenoceras, Garantiana, 

 Baculatoceras, Subparkinsonia, Bigotites, Pscudobigotella, Caiimonti- 

 sphinctes, (Leptosphinctes, V crmisphinctes ?) . 



The evidence of Parkinsonian origin — sulcate periphery — is contained 

 in the inner whorls of Caumontisphinctes and other genera to be named : 

 these whorls also preserve the lateral tubercles of the coronate stage. 

 There is as yet no evidence that Choffatia, Leptosphinctes and Vermi- 

 sphinctes passed through a Parkinsonian stage, though the two latter 

 show evidence of having been coronates : they may have to be removed. 

 Am. martiusii is possibly akin to Leptosphinctes. 



Choffatia, Siemiradzki, 1898, Op. cit. p. 79. "VI. Abtheilung. 

 Subgenus Choffatia nob. Embryonalkammern glatt, comprimirt, ohne 

 jede Spur von Seitenohren. Mundrand wie bei Per. Martinsi abgestutzt, 

 ohrenlos. Seitensculptur ahnlich der Martinsi-Gruppe. Lobenlinie 

 einfach. 



"Diese Gruppe verbindet die Perisphincten mit der Gattung 

 Proplanulites und enthalt eine einzige Formenreihe : Reihe der Per. 

 cobra Waag." (p. 79). 



This marks the genoholotype and there is only one reference to that 

 (P- 334) — " I 875, Perisph. cobra Waagen, Kutch, S. 174, Taf. 45, Fig. I." 

 And this is unique ; from the zone of Reineckia anceps, Kutch, India 

 (Siemir. p. 335). 



Bigotella, Nicolesco 1917 (Bull. Soc. Geol. France (4) XVI, 153), 

 invalid through prior use. 



Bigotites, Nicolesco 1918 (C. R. somm. Soc. Geol. Fr., Jan., p. 36). 

 To replace Bigotella. No genotype indicated in either case, and queries 

 as to his choice addressed to the author gave no result. Therefore 

 Bigoklla thevenini, Nicolesco 1917, op. cit., PL IV, fig. 9 with s.l. fig. 3, 

 p. 178, is now taken as genolectotype of Bigotites. Stout ; ribs somewhat 

 strong, mostly bifurcate ; occasional constrictions ; ribs alternate on 

 periphery, fading into a narrow smooth band which conceals a slight 

 furrow of cast. S.l. has EL much longer than Li, a deep ES which 

 gives obliquity even to Li ; aux 2 about as large as L2, lying across 

 whorl nearly parallel with, but above guide-line ; aux. 3 cut by guide-line. 



Several of the species placed by M. Nicolesco in Bigotella (Bigotites) 

 appear to represent, not a genus in the phylogenetic sense, but a 

 developmental stage — members of different lineages have independently 

 arrived at the periphery with obsolescent interruption, which may be 

 called the Bigotitean stage of venter. If so, this should be revealed 

 by differences of suture-line. The Bigotitean venter is transitional 

 between the Parkinsonian with distinct peripheral interruption and the 

 Perisphinctean with ribs uninterrupted. All the Parkinsonida; which 

 attain the Perisphinctean venter pass through more or less of a Bigotitean 

 stage. But in other families which do not develop the episode of a 

 Parkinsonian venter, the Perisphinctean venter is a continuation of the 

 Stepheoceratan venter : peripheral interruption may appear later. 



Pseudobigotella, P. Lemoine, 191S (Rev. crit. Paleozool. XXVII, 

 (1, 2), p. 34). To replace Bigotella. " M. Nicolesco n'a pas indique 

 de genotype ; la premiere espece decrite est Pseudobigotella Haugi. . . . 

 Je verrais clans tous les echantillons, . . . decrits par M. Nicolesco, 

 une seule espece . . . qui porterait le nom de Parkinsonia Haugi." 

 The author thus makes Bigotella haugi (Nicolesco) the genotype of his 



