Fig. 
Fig. 
Fig. 
Fig. ‘ 
Fig. 
Fig. 
'Fig. 
Fig. 
PLATE II—Continued. 
BARROISELLA, gen. nov. 
Page 62. 
Barroisella suBSPjfTUjL^A,. .Meek and Worthen. 
. The cardinal portion of the pedicle-valve ; showing the conspicuous pedicle-groove, which, in this 
instance, lias beenjSOmewhat widened by compression and fracture; also the articular bosses 
or cardinal fuicra oii’tiie basal margin. X 5. 
. The interior of a pedicle-jvalve ; showing the cardinal area, muscular and o.tne? markings. X 3. 
. The interior of;a'lbrabhial valve, with characteristic features. X 3... 
Black 1 sl4't‘e‘^en!fe!see slate). White River, near Roeifdrd^Ih'di'cCiicl.l 
LINGULASMA, Ulrich. 
i ii . .. Pag? |2i. i .. ; i. i 
Lingulasma Schuciierti, Ulrich. 
. The apical portion of the internal .cast-represented in flgi/22 ; enlarged to show the impression of 
the pedicle-sheath jjps^ oij ii]tergal ( continuation | 0 f ,the caydiijial area. , >< 3. 
. The intenor of a brachial valve ; showing the character of the myscular'iinpressiqns, the platform 
and the very, strbn^.peptum, . Drawn fi ( 'oin a ^utta-percha.impression of,an internal cast. 
Natural size. ' 
. Prolife* view of an internal cast;'showing- the relative thickness of the'platftyms, on the two valves. 
. [The ijntffi-ior.nf..the.pedicle-valves,showi taffid batos)«Ahft indistinctly,defined musquf 
. lar impressions,, tjhe loty, phatfqfin and inpop^piftupysj^ep.tpin. This drawing is,also made from 
a gutta-percha impression.: Natural; size.,, . t-io 
. An enlargement of the surface ornamentation.^. Thq .tjubeycles are sharply.,(leaned, ^nd round, on 
the median portions of the shell, but ^e^ome elongated and l^ss distinct, |;pward the lateral mar- 
• gins. X 5. 
. A natural cast; showingrilie ^nteiior .ofthe^ brachial y^lye. 
;. The opposite side of the same specimen ; showing the. internal, characters of the pedicle-valve. 
Hudson River group. W'Mninptohj'Illinois. 
LINGULOPS; Hall. 
Page "18. 1 
Lingulops Norwoodi, James.: h i 
Fig. 24. The exterior of a pedi^le-valVei. X 4. 
Fig. 25. The interior of a pedicle-valve, di-awn fi-'om a gutta-percha impi'eissioh of a natural 1 cast. The 
pedicle-groove is*faint but evident; within'the broad''posterior margin lie the compound um- 
bonal or cardiflal .impressions ; the scalloped posterior and the median muscular scars are very 
sharply defined. X 8y 
Fig. 26. The interior of a brachial valve ; showing the low, elongate platform. The punctse on the surface 
of the platform appear, ,tOi be regularly arranged, ^)ut. arej probably accidental markings. 
Drawn from a gutta-percha'impressibn.' k 6. 
Hudson River gr.oiipi 1 Cincinnati ; s Ohio. 
Lingulops Whitfieldi, Hall. 
Fig. 27. Th,e, exterior, of .a pedicle-,yalve. X 6. 
Fig'. 28. The interior of a pedicle-valve ; the original specimen. The figure has been drawnTrom a gutta¬ 
percha impression of an intyrria|, past, and. shoyrs, tfie compound cardinal: area (seen also in fig. 
30), the inner portion of which is concentrically striated ; the crescent (cr); the scalloped pari¬ 
etal scar and median muscular scars; the narrow longitudinal septum flanked by broad, rounded 
ridges continued from tlle i 4i , scel'iti'regibn. No tfa'ces ; of vascular impressions are visible on 
. the specimen, ii Xnl2. ' 
Fig. 29. An imperfect interior, probably belonging to the same: (pedicle-) waive." X 12. 
Fig. 30. The interior of the brachial valve] (drawn vfrom a "giitta-percha impression ; showing the double 
cardinal area, a faint pedicle-depression, the crescent (cr), the parietal (?) scars, the platform, 
and the vascular sinuses with their outer ramifications. X 10. 
Hudson River group. Maquolceta CreeJc, 12 miles north-west of Dubuque, Iowa. 
