84 
BULLETIN OF THE LABORATORIES 
and Fenestella cavernosa, Ulrich, are referred to this species. The 
types are from the Keokuk group of Illinois and Iowa. In the collec- 
tion of E. O. Ulrich. 
STREBLOTRYPA MAJOR,! Ulrich. 
(Plate XIV, Fig ro.) 
Sireblotrypa major, Ulrich. 111 . Geol. Surv. vol. VIII, pi. LXXI, figs. 8, 8d, and 
pL LXXII, figs, I, I a. 
The following description of. this species is copied from my MS. 
for the above work ; ‘‘Zoarium a comparatively robust, dichotomous- 
ly or otherwise divided stem. Often found flattened from pressure. 
The divisions of the branches occur at long intervals and are often un- 
equal. Zooecia apertures oval, 0.25 mm. long and about 0.15 mm. 
wide, surrounded by a narrow sloping area, only noticeable in perfect 
specimens ; arranged in longitudinal series (interrupted at more or less 
frequent intervals) between subangular longitudinal ridges, that are 
not distinct from the aperture margin but form their lateral boundaries. 
The longitudinal interspaces between the succeeding zooecia apertures 
exhibit the mouths of from one to three short ranges of mesopores. 
These pores vary considerably in size, and in number from three to 
twelve, but when the zooecial arrangement is regular, their number is 
generally either four or six. Measuring longitudinally, about ten zooe- 
cia apertures occur in 5 mm.” 
‘‘Of internal characters, the comparative shortness of the zooecial 
tubes, the non-development of an inferior hemiseptum, and the rather 
irregular appearance of the tubes in the axial region, are the most 
noteworthy.” 
“The large zooecia and rather robust zoarium easily distinguished 
this species from all others of the genus known to me.” 
tThe genus Sireblotrypa was proposed in MS. by me several^years ago, and 
specimens of the type species, S. Nicklesi, ( 111 . Geol. Surv. vol. VIII), were sent 
to students of palaeozoic bryozoa. The name v^as adopted for a supposed variety 
of the type species by Mr. G. R. Vine, in 1886. (Notes on the Joredale Poly- 
ozoa of North Lancashire). During November or December, 1887, there 
appeared vol. VI of the Palaeontology of N. Y. In looking over this fine work I 
find that Prof. Hall has placed at least one species under his new genus Acantho- 
clema that ought rather to be regarded as a form of Sireblotrypa. The species re- 
ferred to is the Ceriopora hamiltonensis of Nicholson. The typical species of Acan- 
thoclema are quite different, being, like his sub-division Orthopora, closely related 
to Rhombopoj'a. 
