320 
PALEONTOLOGY OF NEW YORK. 
the palaeozoic brachiopodous genera “ will be found in the character of the 
pedicle-passage” (p. 161),^ its conformation and accessories, has been substan¬ 
tiated by all the later investigations of this work,f and is still maintained as 
the true basis of classification. 
It is not the present purpose to recapitulate at any length the substance of 
the deductions already set forth in regard to the Inarticulate genera. The 
views expressed have not been materially modified; but during the interval 
since their publication an extraordinary interest has been manifested in the 
study of the Brachiopoda both recent and fossil, especially in France, Austria 
and America, and the additions thereby made to our knowledge invite special 
attention. 
Lingula has been shown to be a comprehensive type, not existent in pri¬ 
mordial faunas. As yet it is impossible to indicate any difference of generic 
importance between the Lingula of the Lower Silurian and that of existing 
seas. Its elongate form is not primitive, and its complicated muscular system 
is indicative of an advanced stage of progress. We may therefore look for 
the precursors of this type of structure among the less elongate (Lingulella) 
and more orbicular genera (Obolus, Obolella). In the diagrammatic scheme 
of the derivation of Lingula, given upon page 164 of Part I, Lingulella and 
Obolella are represented as divergent from some unknown earlier inceptive 
stock, whose existence, represented by a mark of interrogation, was deemed 
probable from the comparative study of these genera. Such an inceptive form 
would presumptively be wholly elementary in its contour, outline and structure 
of pedicle-opening, and, in fact, be little more than an amplification of the 
infantile condition in its descendants. It has since been observed by Beecher 
* It is proper to explain in this place, that though the title-jiage to Volume VIII, Part I, bears the date 
of 1892, the pages relating to the Inarticulata, including the concluding chaptei' referred to, had been 
completed and printed in .Tuly, 1890. Certain of these (pp. 120-100), I’elating to the structure and devel¬ 
opment of the pedicle-passage in Orbiculoidea, Schizoceania, Tkematis, etc., were reset and issued sepa¬ 
rately at that date, with lithogi'aphic plates (IV e aud IV f), and this printed excerpt was distributed 
among students of the brachiopoda as well as to the general scientific public. 
t The subordinal classification of the Brachiopoda introduced by Waagbn (1883-1885) was based to some 
extent upon the conformation of the xiedicle-jiassage. The phyletic value of variations in this structure was 
first clearly indicated by Eugene Deslongchamps, and has been subsequently elaborated by several 
writers. 
