XVII 



CLASSIFICATION AND AFFINITIES 



487 



Depth in 

 Fathoms 



10 to 690. Bhynchonella psittacea Gmelin 



3 to 808. Crania anomala Miiller . 

 690 to 2425. Discinisca atlantica King . 



Shetland and near Dogger Bank. 



This species is possibly fossil 



as well as recent 

 Loch Fyne, North of Scotland 

 W. of Donegal Bay in 1366 faths., 



W. of Ireland in 1240 faths., 



off Dingwall Bay 



Classification 



The table of classification here appended is that suggested 

 by Mr. Davidson in his Monograph on the Recent Brachiopoda. 



Family 



Terebratulidae. 



I. TESTICAEDINES 



This includes the majority of genera and of species, 

 the latter, without counting uncertain species, 

 amounting to sixty-eight. Examples : Terebra- 

 tula, Terebratella, Terehratulina, Waldheimia, 

 Megerlia, Argiope, Cistella. 



B. Thecidiidae. This family contains one genus, Thecidium, with 



two species. 



C. Rhynchoxellidae. This family is made up of eight species, six of 



which belong to the genus Bhynchonella, and two 

 to Atretia. 



II. ECAEDINES 



D. Craniidae. This family comprises the four species of Crania. 



E. Discinidae. This family contains one species of Discina and 



six of Discinisca. 



F. LiNGULiDAE. This family consists of eight species of Lingula 



and three of Glottidia. 



It is impossible to come to any satisfactory conclusion as to 

 the position of the group Brachiopoda with relation to the rest 

 of the animal kingdom. They have, in accordance with the 

 views of various investigators, been placed in close connexion 

 with many of the large groups into which the Invertebrates are 

 split up. The Mollusca, the Tunicata, the Polyzoa, the Chaeto- 

 poda, the Gephyrea, and of recent times such isolated forms as 

 Phoronis and Sagitta^ have all in turn had their claims advanced 

 of relationship to this most ancient group. As far as I am in a 

 position to judge, their affinities seem to be perhaps more closely 

 with the Gephyrea and with Phoronis than with any of the other 



