Jan., 1893- EVOLUTION OF BRACHIOPODA. 47 



Brachiopod with that most ill-met insect. We adopt the new name 

 for the sake of uniformity, and in order to avoid the undesirable 

 repetition of the bracketed tri-nomen which is making too frequent 

 appearances in modern scientific literature. The substitute possesses 

 the unusual merits of commemorating the exploits of a celebrated 

 navigator, and of indicating at the same time the region of the maxi- 

 mum development of the genus it distinguishes ; for the Magellanian 

 province, as Darwin first pointed out, is remarkable for the great size 

 -of the moUusca inhabiting it, and to this rule the Brachiopoda form 

 no exception. 



First in interest and importance is the report of Messrs. Fischer 

 and CEhlert on the Brachiopoda of the North Atlantic Ocean, which 

 forms the third fasciculus of the fine series of Monographs embodying 

 the results of the scientific explorations of Prince Albert ist of 

 Monaco on board his famous yacht " L'Hirondelle " (5). It gives 

 a critical revision of the recent TerehratulincB, accompanied by exquisite 

 illustrations, and reveals some surprising facts in the general distribu- 

 tion of North Atlantic Brachiopoda, more especially in the Gulf of 

 Gascogny, the archipelago of the Azores, and off the shores of the 

 Soudan (5). The Gulf of Gascogny appears to be one of the richest 

 localities, no less than sixteen species occurring there, including 

 abyssal forms.^ By far the most remarkable among them is the 

 beautiful species founded on a single example first dredged by the 

 " Challenger " Expedition from 390 fathoms off Culebra, one of 

 the West Indian islands, and originally described by Davidson as 

 the largest Terebratulina known (i). 



This is undoubtedly a very interesting type. Fischer and CEhlert 

 had several examples for examination, and were able to study the 

 animal in detail, which was described by Willemoes-S.uhm, in his 

 MSS. notes, as relatively very small. It is now considered to be 

 the type of a new genus, and of a new family (3), " characterised by its 

 non-annulated loop and the arrangement of the arms, which, instead 

 of forming free lobes, are re-united, and, rolled up in the pallial 

 cavity, present a short sub-rectangular disc, a unique feature among 

 the recent Brachiopoda. This disc can be schematically considered 

 as composed of two rudimentary arms, joined laterally, and furnished 

 with a large brachial sinus " (5). The figures now given show great 

 incurvation of the beak area, and thickened margins of the valves — 

 features which are also apparent in Davidson's drawings of the 

 species. Hence we are inclined to consider Dyscolia wyvillii 

 to be one of those atavistic types which Dr. Beecher states occur 

 generally in families after the maximum of genera and species is 

 attained. 



This is a widely-distributed species, ranging from the West 



2 Twice that number of species are recorded, from Japanese and Corean waters, 

 by Davidson in his " Monograph of the Recent Brachiopoda," Trans. Linn. Soc. 

 Zool., vol. iv. (1886-1888), p. 33. 



