M. E. Rigaux — The Brachiopoda of the Boulonnais. 437 



Spirigera Davidsoni, E. Is found only in the shales over the 

 Blacourt limestone at Couderousse. 



Spirifer VerneuilU, Murch. Very common in all the Devonian shales 

 and limestones, offers several varieties ; in the limestones the 

 wings are short, and the beak strongly incurved; in the shaly 

 beds the wings are very long, the area wide, and the beak not 

 recurved ; the variety Archiachi is found only in the higher beds 

 of the Ferques limestone. 



Spirifer Boiichardi, Murch. This species is found under varying 

 forms at three levels ; in the shales of the Cedule quarry it is 

 depressed, larger, and the two ribs that limit the sinus are not so 

 strong as in the second variety which is common at Couderousse ; 

 the typical form figured by Murchison is only found in a par- 

 ticular bed of the Ferques limestone. 



Spirifer TJrii, Dav. Scarce, Beaulieu shales. 



Spirifer Sauvagei, K. Scarce ; is found in the Beaulieu shales with 

 the two following species in the level of Strept. elegans. 



Spirifer Legayi, R. Common at Beaulieu. 



Spirifer Barroisi, n. sp. Scarce, Beaulieu. This species is very 

 near to Sp. Legayi, from which it differs by a less transverse 

 form, a narrower sinus, laminse of growth not so strong, but 

 closer and more nixmerous. 



Spirifer tindiferus, Schn. Very scarce, Beaulieu. 



Cijrtina heteroclyta, Dav. Rather common at the lowest part of the 

 Beaulieu shales, does not seem to go higher than the level of 

 Strept. Bouchardi. 



Cyrtina Bemarlii, Dav. Scarce, Beaulieu shales. 



Spirigerina reticidaris, D'Orb. This is a very common species, and 

 offers several varieties ; Ferques, Blacourt, Beaulieu. 



Spirigerina aspera, M'Coy. Common, Ferques. 



Spirigerina longispina, Bouch. Is only found in the sandy limestone 

 band over the Ferques limestone. 



Bliynchonella Lummatoniensis, Dav. Occurs in the Beaulieu shales. 



Bhynchonella acuminata, Mart. A variety of this species is very 

 abundant in the shales with Strept. elegans ; Beaulieu. 



Bhynchonella Boloniensis, D'Orb. Common in the upper part of the 

 Ferques limestone, and in the sandy limestone over it ; Beaulieu. 



Bentamerus brevirostris, Phil. Is found commonly in a small calca- 

 reous band below the Ferques limestone. 



Orthis striatula, D'Orb. Common everywhere, Ferques, Beaulieu. 



Orthis Deshayesii, Bouch. Very common in the level of Strept. 

 Bouchardi. 



Orthis Dumontiana, Vern. Common in the same bed. 



Orthis Eifeliensis, Sch. Scarce, is found with Bent, brevirostris at 

 Beaulieu. 



Streptorhynchus Devonicus, Dav. Common at the highest part of the 

 Ferques limestone. 



Streptorhynchus elegans, Bouch. Very common, distinguishes a 

 particular level in the Beaulieu shales. 



Streptorhynchus Bouchardi, R. Very common, Beaulieu shales- 



