H. L. Hawkins — Jaw-structures in Conulus. 71 



lantern), and, basing his observations on some specimens in the British 

 Museum, maintained that the teeth described by Forbes were 

 imaginary, or founded merely on grooves caused by a tool in the soft 

 chalk within the peristome. As a result of his conclusions he placed 

 ' Galerites ' among the Echinonidse. 



Following on so uncompromising a denial, almost all subsequent 

 writers have regarded Conulus as a toothless form. In 1900 Gregory 

 took this view (Gregory, 1900, p. 316), although retaining the family 

 Graleritidse among the Holectypoida, while in the same year Sladen 

 placed the genus among the Echinonidse (Sladen, 1900). 



"With the exception of the last two references, which are of 

 a general character, all the discussion was concerned with Conulus 

 aloogalerus, one of the latest members of the genus, and certainly the 

 most readily obtained and studied in this country. A small, tumid 

 form of this species is very abundant in the uppermost layers of the 

 zone of Micraster coranguinum in the South of England. I recently 

 collected more than fifty specimens from this ' Conulus band ' in 

 a chalk-pit near Kingsclere, and neither in the interior of the 

 specimens nor in the matrix in which they were so thickly scattered 

 could I detect the smallest trace of any structures comparable with 

 normal Echinoid jaws. In the case of one specimen, in which the 

 buccal plates were in situ, and by their presence narrowed the mouth 

 opening to a very small circle, there was no macroscopic fossil inside 

 the test excepting two stray buccal plates which must have drifted in 

 with the infilling chalk. 



I made this search as a result of the discovery by the late A. Agassiz 

 of teeth and a lantern in a young specimen of Echinoneus (Agassiz, 

 1909). After having destroyed fifty specimens and rubbed down 

 (with a brush) a very considerable quantity of their matrix with no 

 result, I came to the conclusion that Duncan was justified in his 

 scepticism. It was therefore with great surprise that, on examining 

 a series of Conulus suhroUmdus, Mantell, in the British Museum, 

 I found a specimen 1 with the peristome enlarged by cutting and four 

 glistening, enamel-like teeth projecting towards the aperture. "Whether 

 this specimen is the one on which Forbes based his account of teeth in 

 the newer species, or not, is a question which seems unanswerable. 

 There is no information as to the locality from which the specimen 

 was collected, nor as to whose hand cleared out the peristome. (The 

 only information with the specimen was ' Upper Chalk ', which is 

 almost certainly inaccurate.) If, however, this should be the example 

 referred to, the figures given in the Decade (pi. viii, fig. 10), and 

 subsequently copied by d'Orbigny and Wright, owe a great deal to 

 the imagination of the artist. 



The specimen is of the form of C. sulrotundus, found most frequently 

 in the zone of Terelratulina, being tall, inflated at the sides, and 

 rounded at the margin of the adoral surface. Judging from the 

 intense hardness of the chalk within the test, it would seem to belong- 

 rather to the zone of Rhynchonella Cuvieri. It is, at least, safe to 

 ascribe it to the Middle Chalk. It seems to be fully adult. For 



1 The specimen has been registered E. 10743. 



