10 EINAR LONNBBRG, ANATOMICAL NOTES ON EAST AFRICAN MAMMALS. 



north of Guaso Nyiri ^*/2 1911 were preserved and enable me thus to give the fol- 

 lowing notes. 



The paunch is not, even comparatively speaking, large. The width across both 

 sacks is about 12 cm. and the length of either of the subequal sacks is a little more 

 than 11 cm. The dorsal sack is much broader than the ventral, especially if the 

 fundus ends are compared. The fissure between the latter does not appear to be 

 more than about 2 cm. deep, but this depends upon the fact that their walls are 

 connected, and if this connection is removed the fissure is found to be fully 47^ cm. 

 even exteriorly. The exterior sculpture of the paunch is not very pronounced. On 

 the right side the longitudinal furrow, the posterior transversal furrow {sulcus- coro- 

 narius caudalis ventralis) of the ventral sack, and the anterior transversal furrow are 

 well developed. On the left side the longitudinal furrow is most visible. The in- 

 terior of the paunch is densely clothed with flat, tongue-like papillae which are larger 

 in the dorsal sack. 



The contents of the paunch consist of remains of leaves and beans of acacias, 

 the latter swallowed whole, although measuring 14 X 13 mm. 



The reticulum measures about 6x5 cm. The cells of the reticulum which 

 generally have a diameter of 6—8 mm. are bordered by very low septa which more 

 resemble rows of somewhat enlarged papillae with confluent bases than real septa. 



The kidney-shaped psalterium measures 54 mm. in length, 37 mm. in height 

 and 24 mm. in thickness. Compared to the size of the animal this organ is thus 

 quite large, and its longest diameter is not much less than that of the reticulum. 

 The size of the psalterium of this species is quite remarkable, if it is considered that 

 the same organ in the much larger Indian Blackbuck {Antilope cervicapra) is 45 X 30 

 X 25 mm., in Cephalophus ogilhyi 60 X 30 mm.,^ in C. natalensis 54 x 35 mm. in 

 Bhaphicerus campestris 35 X 20 mm.^ In such a small species as Cephalophus mela- 

 norheus the dimensions of the psalterium are 25 X 15 mm.^ But in all the species 

 enumerated the reticulum has nearly, or sometimes more than, twice as long diameter 

 as the longest diameter of the psalterium. These facts appear to indicate that the 

 functions of the reticulum and the psalterium are different with regard to their im- 

 portance to the species mentioned above and to Rhynchotragus guentheri wroughtoni. 



The psalterium of the latter has about 7 strongly developed primary folds. 

 The secondary folds are low, and tertiary folds are only found as slight traces in a 

 few loculi. The folds are beset with sharply pointed papillae and extend through the 

 greatest part of the lumen of the organ. It is thus evidently a comparatively powerful 

 organ for grinding and triturating the food-material to facilitate the digestion. The 

 great development of this organ stands probably in connection with the occurrence 

 of this Dikdik in a dry region where during a long time of the year tender vegetable 

 food is not to be obtained. The presence in the ventricle of the acacia-beans men- 

 tioned above may also give an explanation of the function of this organ. 



1 LOnnbeeg: Nova Acta Reg. Soc. Sc. Upsala. Ser: III. 1903, p. 4 & 19. 



2 Idem: Ark. f. Zoologi. Bd. 5. N:o 10. 1909, p. 11 & 12. 

 =* Idem: 1903, p. 17. 



