276 PROCEEDINGS OF THE ACADEMY OP 



chell, at Chicago, and requested him to re-examine his typical specimens 

 of Syringothyris, to see if he could discover any traces of punctures. 

 He afterwards informed me that he had done so, hut could see no evidences 

 of punctures, and he kindly gave me a slip of glass upon which wete fastened, 

 with Canada balsam, fragments of his typical species and of another not yet 

 described, in neither of which any punctures were visible. 



In this connection, however, it is proper to remark, that all of these frag- 

 ments are either very small, or so opaque and badly preserved, that the punc- 

 tures might not be apparent, even if ihey exist. It is also worthy of note 

 that in several shells of this type which I have examined, the punctures are very 

 small, and so distant that fragments large enough to show clearly the punctures 

 as seen in the various types of Terebratulidce, might be without a single punc- 

 ture. From these facts, and others to be mentioned farther on, I am strongly 

 inclined to think Prof. Winchell's specimens are not in a good condition 

 for showing the shell structure, and without intending to attribute any care- 

 lessness or want of discrimination to that gentleman, that tjiese species may 

 yet be found to be punctate when other specimens in a better state of preser- 

 vation are obtained. 



On looking farther through Mr. "Worthen's collections, I saw other species 

 of this type, and examined their shell structure with the following results : 

 first, a form from Missouri, believed to be Spirifer subcuspidatus, Hall, 

 from the Keokuk division of the subcarboniferous series, (and thought by 

 Mr. Davidson, from an examination of examples from Illinois, to be identical 

 with European forms referred to S. cuspidal us), was examined, and found to 

 be unquestionably punctate. The punctures are small and scattering, but 

 owing to the fact that they were, in the specimens examined, filled witli dark 

 opaque matter, they could be very clearly seen by transmitted light, in thin 

 fragments saturated with Canada balsam. The interior of this shell is unknown 

 to me. 



Next, specimens of apparently another species or variety, (scarcely, if at 

 all, distinguishable, by external characters at least, from certain forms of S. 

 cuspidatus as usually understood), from the fine-grained sandstone of the 

 Knobbs, back of Albany, Indiana, were examined, and also discovered to be 

 clearly and unquestionably punctate, the punctures being small and scatter- 

 ing as in the. last. Internal casts of this shell, from the same locality, show 

 it to possess exactly the internal characters of Syringothyris, Winchell. 



Having thus found the punctate structure clearly visible in the several 

 American forms mentioned, a specimen of S. cuspidatus, sent by Mr. Davidson 

 to Mr. Worthen from Millicent Island, was examined, and quite unexpected- 

 ly found to be also clearly punctate, like the American forms. This Irish speci- 

 men is not in a condition to show the interior, but on removing some of the ma- 

 trix from the foramen it was found to possess, near the beak at least, the trans- 

 verse plate, or deep-seated false deltidium, seen in Syringothyris, though it was 

 impossible to determine, without spoiling the specimen, whether or not the 

 characteiistic tube exists in connection with its inner side. 



Now when it is remembered that as careful, conscientious, and accurate an 

 observer as Dr. Carpenter, has pronounced the structure of Spirifer cuspidatus 

 impunctate,* after a thorough examination, the question naturally suggests 

 itself, whether there may not be two closely similar, but really very distinct, 

 British types confounded under the single specific name S. cuspidatus ? that 

 is, one with a punctate structure and another without it. If so, and the punctate 

 structure is here, as I am much inclined to believe, coincident with the pecu- 



* After speaking of the fact that Mr. Davidson hail, on other grounds, divided the Spirifer 

 group into sections, which it was also found could he distinguished by their shell structure, Or. 

 Carpenter remarks that " under the subgenus Ci/rlia, he [Mr. Davidson] places these impunctate 

 species, which, like C. Irapczoidalis. have a perforation for the pasi-age of a pedicle; besides these 

 tpecies 1 have examined C. cuspidata, [= Spirifer cuspidatus,] h:h1 am fully satisfied that in 

 neither of these do any perforations exist." (Davidsoii's Introduction lo the Classification of t/t* 

 Bradneipuda,p. C4. 



[Dec. 



