1922] Allen, Congo Scivridae, Anomaluridse , Idiuridde 53 



Niangara were all taken in November; five others from Avakubi were 

 taken October 7 to November 24; five from Medje were also taken 

 near the same season (September 26, October 5, and January 18-24). 

 When laid out in two series, the specimens from Niapu in one and 

 those from the other localities in the other, it is seen that only a few 

 of the most heavily colored specimens from the eastern localities equal 

 the palest of the Niapu series in either the extent or intensity of the 

 ochraceous wash of the ventral surface. While a few of the lighter 

 colored specimens in the Niapu series can be matched by a few of 

 the darkest specimens in the other, and thus indicate intergradation, the 

 average difference is striking, particularly when the palest specimens of 

 the two series are compared. It seems desirable therefore to recognize the 

 Niapu series in nomenclature as a saturate type of the group, especially 

 since a pale form of anerythrus (F. a. bandarum Thomas) has been desig- 

 nated from the upper Shari River. 



In the present connection it may be of interest to give the results of a 

 comparison, especially in respect to size, of the F. pyrropus akka series 

 of thirty-two specimens with the fifty-two of the F. anerythrus group, 

 since both were collected at the same time at about the same localities. 

 First it may be stated that the two forms of anerythrus show no differ- 

 ence in size, and the same is true also of the akka and anerythrus series, in 

 either external or cranial measurements. Nor am I able to distinguish 

 the skull of akka by any feature from the skull of anerythrus. In the 

 coloration of the upperparts there is also a close resemblance, the chief 

 distinction being the color of the lateral line, which is pale buffy in akka 

 and white in anerythrus, often indistinct in both. The tail is also alike 

 in both, on both surfaces. But the difference in the color of the outside 

 of the limbs (including the upper surface of the feet) and the ventral 

 surface is striking. In anerythrus the legs and feet externally and the 

 sides and front of the head are brown with a dull cinnamon-rufous suffu- 

 sion; in akka intense brownish lufous, particularly on the hind limbs and 

 feet. In anerythrus the whole ventral surface and inside of limbs is 

 heavily washed with ochraceous (ochre-yellow to ochraceous rufous), 

 the basal third of the hairs pale plumbeous; in akka everywhere clear 

 white to the base of the hairs. 1 As both anerythrus and akka live together 

 abundantly at all localities from which either is represented in the 



'The Xiangara series, as might be expected, is the palest of all, but the Avakubi specimens merge 

 with them; the palest specimen is an old male from Avakubi, taken October 7, which is white below 

 with a slight buffy wash over the thoracic region. 



