Dr. A. Krolin on Glandular Sacs in the Phalangiidge. 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 

 Ckrafodus, but correspond in every respect to Ctenodus, except 

 in the deficiency of tubercles or denticles on the ridges. 



7. Ctenodus ellipticus^ n. sp. 

 Tooth flattened, thin, elliptical. If inch long and | 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 fuiTOws 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 

 punctured. The mandibular tooth is narrow, with the inner 

 border 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. ivd)ricatus ; 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 m the Cephalo- 

 thorax of the Phalangiida3. By Dr. A. Keohn*. 



On the dorsal shield of the cephalothorax of the Phalanguda', 

 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 point 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, S. DaUas, F.L.S., from Wiegmann's Archiv, 1867, 

 pp. 79-83. 



