from the Quanza and Bengo Rivers. 539 



new species of Petersius and the pretty little new Barbus 

 musumbi. 



(< Exploration of the Quanza River at Cunga, Dondo, and 

 Cambambe gave also valuable results. The Ciehlid perches 

 Tilapia flavomarginata and Tilapia cabra are very delicious 

 eating ; they are plentiful at Cunga and form a highly 

 appreciated commercial commodity, both fresh and sun- 

 dried, under the local names of ' shopa ' and ' cacusso.' 

 The single specimen of the new Petrocephalus cunganus as 

 well as the single specimen of the large red-brown Lutjanus 

 eutactus were captured at Cunga. The casting-net secured at 

 Dondo the single specimen of the new Syngnathus, the two 

 tiny specimens of Ilaplochilus macrurus, and quite a number 

 of the new Barilius. Cambambe is a mountainous region 

 where the River Quanza forms rapids ; below these rapids 

 the new Physailia and the two new species of Chrysichthys 

 were obtained by using dynamite. 



" In recognition of the kind assistance given by His 

 Excellency Lieut. -Colonel Jose Augusto Rocadas (Governor- 

 General of Angola) and by Senhor Manoel Francisco da 

 Costa Sertio (Director of the Companhia de Camino de Ferro 

 Atravers Africa), three of the new species have been named 

 Labeo rucadasi, Barbus rocadasi, and Chrysichthys seraoi 

 respectively. Similarly, Barbus roses has been named in 

 honour of the Vicar Padre Anastacio Luis Rosa for helpfu 

 courtesy during a seven years' friendship." 



Mormyridae. 

 1. Petrocephalus simus, Sauv. 



Quanza River at Cunga and Lucalla River at Kalenge. 

 Native name : Dilele. 



2. Petrocephalus cunganus, sp. n. 



Depth of body equal to length of head, 3^ times in total 

 length. Head slightly longer than deep, with convex upper 

 profile ; snout rounded, strongly projecting beyond mouth, 

 1 length of head ; mouth below anterior border of eye, its 

 width \ length of head ; teeth bicuspid, 11 in upper jaw, 

 24 in lower ; nostrils near lower border of eye ; eye £ length 

 of head, § interorbital width. Dorsal 27, originating above 

 first ray of anal ; its length 1 1 times in its distance from 

 head and a little greater than its distance from caudal. Anal 



36* 



