214 Professor H. L. Hawkins — 



indistinct on the lower surface," agree with Lambert's phrase " ces 

 tubercules s'atrophient a la face superieure " ; the " compact apical 

 system with five apparently equal genital plates " is transformed 

 into the " peristome extremement etroit, a scissures interambulac- 

 raires en fentes assez profondes " (Lambert) ; and the " central, 

 exceedingly large peristome " is the " apex tres large, occupant une 

 grande partie de la face superieure ". The only discrepancy in the 

 two diagnoses unsolved by this inversion is in the description of 

 the ambulacral pores, which, to Fucini, appeared diverse (" pori 

 della serie interna sono spiccati e rotundi, quelli della serie esterna 

 molto allungati obliquamente "), and to Lambert, " pores simples ". 

 Possibly imperfect preservation misled Fucini ; anyhow, Lambert's 

 account seems to me the more credible. 



The foregoing lengthy comment on an obscure and confusing 

 genus is necessary in view of the two specimens on Avhich this 

 paper is based. Some months ago my friend Professor D. M. S. 

 Watson told me that he had seen, in the British Museum, two 

 " Pygasters " in a collection of Persian Liassic Ammonites entrusted 

 for study to Dr. F. L. Spath. At the earliest opportunity I sought 

 out Dr. Spath, and the collection was promptly and courteously 

 displayed. After the sensation of disappointment at the state of 

 presei^ation (if such it can be called) of the specimens had somewhat 

 abated, desperate examination of the less imperfect example was 

 undertaken. Soon it appeared that most features of importance 

 were more or less accessible, and that the labels attached to each 

 specimen (" Pygaster, Kelat ") were not so grotesquely inaccurate as 

 had seemed probable. It was obvious that the name Pygaster, even 

 in its widest sense, could not be applied to the form ; but the 

 periproct was typically Pygasterid, in form, and position. 



At the time of this preliminary view of the material, I had 

 not seen Lambert's revised account of Lorinlella, and several years 

 had elapsed since I had read Fucini's paper. However, Loriolella 

 was the only type that commended itself to my memory as com- 

 parable with the specimens before me. Mention of its name gave 

 a pleasant surprise to Dr. SjDath and myself. He explained that the 

 Ammonite fauna from Kelat showed striking affinity with that from 

 the Italian Lias, and that Fucini's monographs were in constant 

 use for purposes of comparison. So that both of us were confirmed 

 in our views by this unexpected coincidence. 



Almost persuaded that the Persian Echinoids would prove con- 

 generic with L. ludoxnci, I renewed acquaintance with Fucini's 

 paper (1904, Ann. Univ. Tosc, xxiv). Point by point the new 

 specimens were compared with the description of the Italian type, 

 and in many respects the agreement was extraordinarily close. But 

 the " peristoma grandissimo " of Fucini's diagnosis seemed to 

 counterbalance all the approximations, for the small size of that 

 aperture is one of the most striking features of the Persian form. At 

 that stage of study, the Kelat Echinoids seemed to represent a new 

 genus closely akin to the " Exocyclic " Loriolella. 



