Dr. A. Krohn on Glandular Sacs in the Phalangiide. . 87 
This species is not common: I have found only six or seven 
specimens of it; they were all obtained at Newsham. Two of 
these, an upper and a lower, are large and in an excellent state 
of preservation ; the others are quite small, but, like the large 
ones, have six ridges, and agree with them in every particular. 
_ This and the following species have some resemblance to 
Ceratodus, but correspond in every veeper to Ctenodus, except 
in the deficiency of tubercles or denticles on the ridges. 
7. Ctenodus ellipticus, n. sp. 
Tooth flattened, thin, elliptical, 13 inch long and 3 inch broad; 
the inner and outer margin irregularly arched; the surface 
with five transverse, smooth, distant, angular ridges, in- 
creasing in size towards the outer margin; the furrows are 
wide and round, and the anterior and posterior margins of 
the tooth are extended a little beyond the ridges before and 
behind ; the whole surface, including the ridges, is minutely 
unctured. The mandibular tooth is narrow, with the inner 
einies gibbous; in other respects it agrees with the upper 
or palatal tooth. 
The maxillary bone is considerably more than twice the 
length of the tooth, and has the posterior extremity greatly 
expanded and truncated. 
Five or six specimens of this tooth have come into my pos- 
session. ‘They occurred at Newsham, and are all fully deve- 
loped and in good condition. 
This well-characterized species is not likely to be mistaken 
for any of those above described. ‘The only one with which it 
might possibly be confounded is C. imbricatus ; but the com- 
parative thinness of the plate and the non-imbrication of its 
ridges sufficiently distinguish it. 
XIII.—On the presence of two Glandular Sacs in the Cephalo- 
thorax of the Phalangiide. By Dr. A. Kroun*. 
On the dorsal shield of the cephalothorax of the Phalangiide, 
close to each of its lateral margins and a little way from their 
junction with the anterior margin, there is a rounded elongate 
_ Opening, which was observed by Latreille, and through which 
the eae of a fine needle may easily be passed to a certain 
depth. Each of these apertures is surrounded by a thickening 
_ of the integument projecting in the form of a wall or chitinous 
* Translated by W. 8S. Dallas, F.L.S., from Wiegmann’s Archiv, 1867, 
pp. 79-83. 
