122 



ilASTACEMBELID-E. 



Total length 370 millim. 



Ubanghi and South Cameroon —Types in Congo Museum, Tervueren. 



1-2. Ty[.es. Banzyville. <^''^pt- Royaux (C). 



3-4. Ad. Nyong R., S. Cameroon. 



G. L. Bates, Esq. (C). 



Fis. 



Alastacem helus ansonjii. 

 Type. |. 



10. MASTACEMBELUS ANSORGII. 

 Boiileng. Ann. &. Mug. N. H. (7) xv. 1905, p. 459. 



Depth of body 20 times in total length, length of head 8g times. 

 Vent equally distant from end of snout and from caudal, its distance 

 from head ^ length of latter. Snout 3^ times as long as eye, ending 

 in an appendage which is as long as eye ; mouth extending to below 

 centre of eye ; no praeorbital spine ; 2 or 3 strong prseopercular spines. 

 Dorsal XXXIV 128; spines increasing in length to the last, which 

 measures 1^ diameters of eye ; distance between first spine and head 

 ^ length of latter. Anal II 120. Caudal rounded. Pectoral j length 

 of head. Scales very small, 20 between origin of soft dorsal and lateral 

 line. Olive-brown above, yellow beneath, with dark brown spots and 

 marblings ; three series of large spots on the back, the lateral series 

 confluent into a wavy band on the tail ; below these spots a straight 



