M. J. Frciizcl on the Mesozoon Salinella. 79 



Tail long-cr than tlio head and body, brown above, pen- 

 cilled with black terminally, orange-rufous on the sides and 

 below. Pahns and soles with the essential characters of 

 those of O. gracilis^ leucogaster, &c., i. e. naked, with five 

 anterior and four posterior pads, but distinguished from all 

 the species of this group by the fact that a band (about 4 

 millim. broad) of fine hairs passes across the soles at about 

 the level of the base of the hallux. Skin of soles black. 



Skull very much as in U. gracilis. Bullae small, egg- 

 shaped, their posterior part scarcely swollen. 



Teeth : upper incisors much bevelled, each with one deep 

 groove. Molars with the low, distinct, directly transverse 

 lamina3 characteristic of this group of Gerbillcs. 



Dimensions of the type (an adult specimen in skin) : — 

 Head and body 140 millim. ; tail 155 ; hind foot 29. 



Skull : basal length 30 ; greatest length 35 ; tympanic 

 breadth 16*5 ; nasals, length 14, breadth 3*7 ; intcrorbital 

 breadth 6 ; interparietal, length 4, breadth 8"5 ; palate, length 

 18*5, diastema 10, palatal foramen 0*1 ; length of upper molar 

 series 5*2 ,• greatest diameter of bulla; 10'4 ; vertical height of 

 brain-case and bull£e combined 13*5. 



Hab. Wadelai. 



Type (87. 12. 1. 50) collected and presented by Dr. Emin 

 Pasha. 



A second specimen, collected at the same time and place, 

 agrees in every respect with the type. 



These two specimens were presented to the Museum with 

 Emin Pasha's first collection (see P. Z. S. 1888, p. 10, 

 no. 24). Turning out now to be new, it is only just that 

 they should receive the name of their distinguished discoverer. 



XII. — The Mesozoon Salinella. 

 By Johannes Feenzel *. 



It is a well-known fact that between unicellular and multi- 

 cellular animals there hitherto stretched a gulf which was 

 wider than that between the vegetable and animal kingdoms, 

 for indeed the two latter, in spite of the advances which we 

 have made in knowledge, are even to-day hardly separable 

 from one another. The unicellular animals, usually com- 

 prised under the name Protozoa, and embracing besides many 

 doubtful forms of the Protista, not only consist, as their name 



* Translated from the ' Biologisches Centralblatt,' xi. Bd. no. 19 

 (October 16,1891), pp. 577-681. 



