174 1 IK' Ann mil II (itnlmiist. S.'pt.-iiili.'r. 1S!M 
'Pill' jii'in-nil outliiH' of the piiltis mikI iscirmiii is iiiiicli like tlint 
ill I'lrsiiixiiiniis ;is liiiurcil hy lluxicv*. tlioiiiili its dctnils (lillcr. 
'I'lu' lihuU' of the jmliis is a warped plate. pn'seiitiii<r. wlieii viewed 
from aliovi'. two coneavities separated by an aiitero-postei'ior axis 
of convexity, the major eoiivexity eiiihraeiiisi; a lar<re pail of tlu> 
middle and inner anterior reiiioiis. the minor oceiipyiiiif a small 
onter-anterior part. 
Knt tliepelvie arch possesses one featnre that distinguishes it 
from any described sauroptervgitiii pelvis with which the writer is 
ac([uaintedt. The ilinm does not articulate with, nor even clo.sely 
approach, the pubis, being separated from it by the acetabular 
portion of the ischium, of whose acetabular face its own forms a 
posterior continuation. Thus the three elements of the aeetal)U- 
lum are brought into line. 
TiiK Vkrtkbr.e. — To what has lieen pulilished concerning the 
vertebne, there is l)ut little that need be aiUU'd here. As would 
lie inferred from the great si/ce of the skull, the aliterior cervical 
verteline are not greatly reduced in size. The atlas and axis and 
their intercentrum are anehylosed. but their sutures persist. The 
i-ervical ribs are suturallv adiiate to the centra bv siiiii'le facets. 
ON THE CONFOUNDING OF .V.I.s.S.I TIUVIITATA ^\\ 
AND.VJN.s.l /'/•;/.'. I />'/'. I (CON. SP.) 
By (iiLBEiiTl). Hakko. Washington, D. I'. 
Xiiasa trlriftdtii. a recent species inhal)iting the eastern coast 
of the Uuited States, was descrilied in the second volume of the 
.Journal of tlu' IMiihuU'lphia Academy of Natural Sciences, in 1S22. 
by Thomas Say.** 
Eight years later, a somewhat similar though very distinct form 
obtained from the -Upper Marine" (Miocene) formation in the vicin- 
ity of St. Mary's River. Md.. was inadvertently referred by (\)nrad 
U)--X<i!<s<i Triritt<it<i. Say.'tt Morton ri'pt'aled this error on page 
1 of the Ai>i)endix to his Synopsis of the Organic Remains of the 
Cretaceous (iroiip. pulilished in IS.'U. The species is again re- 
ferred to by ("oiirad in 1 S42 under the name ••Burrinmii trlrittn- 
* Vertebrate Anatomy, p. 182. 
tin EliiKiiiDHiiiiruK, the ilium is ilpscribed by Cope as articulatinii with 
the pubis only. Extinct Heptilia, 15atra( hia and Aves of Nortli America, 
p. 52. 
**0p. cit. 1822, p. 281. 
ttlbid., VI., 183U, p.211. 
