34 JURASSIC RHYNCHONELLIDS 
Internal characters. Pedicle valve. Shell massive and the muscle impressions 
deeply inserted. The teeth are strongly developed and lateral denticulae are present. 
Brachial valve. Typical lacunosellid falcifer crura are developed. Very strong 
inner and outer socket ridges are present. 
DISTRIBUTION. The species has been collected by the author from the southern 
French Jura in the Départments of Savoie and Isére and from the Franconian Jura. 
Two of the specimens from Poland figured by Wisniewska (v. synonymy) as Septali- 
phoria pinguis are externally identical with L. vaga and, as they also come from the 
same horizon, it seems very likely that Wisniewska misattributed them. This 
suggestion is borne out by the fact that Royzicki (1948) recorded S. pinguis sensu 
Wiésniewska from sponge reefs. If this is the case, then the geographical distribu- 
tion of the species would be considerably extended. 
OccURRENCE. At the type locality, L. vaga is associated with Torquirhyncha cf. 
astierifornuis and details of the locality are given under that species. The specimens 
collected from the Col du Chat (Savoie) were from fine-grained, bioclastic limestones. 
This record is interesting in that it is the only occurrence of Lacunosella known to 
the author where the genus is not associated with sponges ; many of the specimens 
were crushed and the only other fossils collected from the locality were terebratulids. 
The Franconian material was found with the typical association of sponges, ammo- 
nites, terebratulids and lamellibranchs at the base of a small reef. 
Lacunosella cracoviensis (Quenstedt) 
(Pl. 2, figs. 5-6, text-fig. 15) 
1871 Tevebvatula trilobata cracoviensis Quenstedt: 136, pl. 40, fig. 43. 
1871 Tevebvatula lacunosa subsimilis (Schlotheim) ; Quenstedt: 129, pl. 39, fig. 78. 
1917 ?Rhynchonella cracoviensis (Uhlig); Rollier: 172. 
1917. Rhynchonella prosimilis Rollier: 174. 
1932 Lacunosella cvacoviensis (Quenstedt); Wisniewska: 41-46, pl. 2, figs. 6-20. 
EMENDED DIAGNosIs. Medium-sized, subpentagonal Lacunosella ; prominent 
narrow, suberect beak ; 17-25 fine, bifurcating ribs ; crura falcifer. 
STRATIGRAPHICAL RANGE. Upper Oxfordian—Lower Kimmeridgian ; in Swabia 
and Franconia it has been recorded from the “ beta”’ and “‘ gamma Malm ”’ while 
Wisniewska gives its range in Poland as “‘ Sequanien ”’. 
TYPE SPECIMEN. Lectotype, here selected, fig. 43, pl. 60 in Quenstedt (1871), 
from the “ Coralrag ”’ of Przegorzaty, Poland. 
MATERIAL. 7 specimens, collection of Tubingen University from Swabia ; 21 
specimens, author’s collection from Franconia and Swabia, in the British Museum 
(Nat. Hist.) nos. BB. 45650-67, BB. 45674-77. 
Description. External characters. L. cracoviensis is a medium-sized Lacuno- 
sella ; although the outline is subpentagonal, it shows considerable variation and 
either length or width may be the greater dimension. 
The subangular ribs are relatively fine, commence at the umbones and are often 
bifurcate. The anterior commissure is usually symmetrical with a low uniplication 
