292 Prof. A. Nehring on Myodes lemmus crassidens. 



The present species is distinguished from those previously 

 described in the form of the cephalon and structure of the 

 metasome, in the remarkable structure of the fourth joint of 

 the antenna?, and the details of the uropods. 



I have named the species after my friend M. A. Dollfus, 

 who has done such excellent work among the Isopoda. I 

 am indebted to the kindness of the Rev. Arthur Cole for the 

 illustrations in the Plate. 



EXPLANATION OF PLATE V. Figs. 2-8. 



Fig. 2. Female, magnified. The natural length is shown by the side of 



fig. 2. 

 Fig. 3. An antenmile. 

 Fig. 4. One of the antennae ; the three short basal joints of the peduncle 



are omitted. 

 Fig. 5. One of the maxillipeds. 



Fig. 6. Inner member of the first pleopod of the male. 

 Fig. 7. Right uropod. 

 Fig. 8. A perseopod. 



XXX. — On Myodes lemmus crassidens, var. nov.foss., from 

 Portugal*. By Professor A. Nehring. 



In the year 1896 Barrett-Hamilton published in the ' Pro- 

 ceedings ' of the Zoological Society of London, pp. 304-306, 

 an interesting communication on the remains of lemmings 

 from a cave which is situated at Athouguia, Portugal, not 

 far from Santarem, in the province of Estremadura. 



As the remains of lemmings which I have myself dug up 

 and even examined amount to thousands, I was consequently 

 extremely desirous of seeing the Portuguese lemming-remains ; 

 through the kind offices of Mr. Barrett-Hamilton in London 

 and Dr. Harmer in Cambridge I went to the Zoological 

 Museum of the University of Cambridge, so that I am able to 

 speak from personal observation f. Secondly, owing to a 

 letter from Dr. Gadow, I had the welcome opportunity given 

 me of making some more exact observations on the discovery. 



1 examined the remains of six examples, which were 

 represented by five crania (of wliich four had the corresponding 

 lower jaw), several half mandibles, as well as a number of 



* Translated from the 'Archiv fiir Naturgeschichte,' vol, i, part 2 

 (1899), pp. 175-182, by Wilfred Mark Webb, F.L.S. 



t I have already published a short preliminary notice of these 

 Portuguese lemming-remains in the ' Sitzungsbericht d. BerJ, Ges, 

 naturf. Freunde ' of March 21, 1899. 



