42 THE BEAOHIOPODA. 



Localities. Bradford Abbas, Broadwindsor, &c. (Dorset), 

 characteristic of the top sub-division of the inferior oolite (zone 

 of Cosm Parkinsoni) also Dinnington. 



43. EHYNCHONELLA CYNOCEPHALA, Richard. 



1851. EHYNCHONELLA CYNOCEPHALA, Davidson, British Brach. 

 Palseont., Soc., plate xiv., fig. 10-12. 



1877. CYNOCEPHALA, Davidson, Proc. Dorset Club, 



Vol. I., plate iv., fig. 16. 



1877. STEPHENSI, Davidson, Proc. Dorset Club, 



plate iv., fig. 13. (The young state of 

 Rhynch. cynocephala.} 



Mr. Davidson in the " Proceedings of the Dorset Club " says, 

 "This appears to be an uncommon species in the inferior oolite 

 of the Bradford Abbas district, for I found only one example of 

 it among upwards of a thousand specimens I had under exami- 

 nation. It was found by Mr. Darell Stephens at Crewkerne 

 Station.* Since this was written, however, the proper beds for 

 Rhynch. cynocephala have been examined, and it is found to be a 

 common fossil. Unfortunately the zone in which it occurs most 

 plentifully (the zone of Harp. Opalinum) is only exposed at 

 three places, the coast of Burton Bradstock, and at Stoke Knap 

 in Dorset, and near Haselbury (Somerset). This species alfeo 

 certainly occurs, but very rarely, in the zone of Harp. Murchi- 

 sonse. The common form of this species is the form with two 

 plaits, but specimens with only one, and also with three, have 

 been found. The variety with one plait occurs in the Murchi- 

 sonse zone at Drimpton (Dorset) by itself (that is to say, I did 

 not observe the usual form there at all) and also in other places. 

 The mesial fold of our specimens is generally not so much 

 raised as in those from Gloucestershire, and as far as we have 

 yet found they are slightly smaller. 

 * Davidson, Proceedings Dorset Club, Vol. I., p. 86. 



