ETHIOPIAN NASUTITERMITINAE 75 



MYCTEROTERMES gen. n. 



(Mycteros, Gr., " beak ") 



Type-species, Mycterotermes meringocephalas sp. n. 



Imago. Unknown. 



Soldier. Dimorphic. Major soldier, nose short, cylindrical, vestigial mandibles with small 

 but distinct points showing trace of marginal as well as apical tooth ; head capsule very weakly 

 constricted behind antennae, vertex and nose with short but distinct bristle-like setae. Minor 

 soldier, as major soldier, except nose weakly conical, head capsule more definitely constricted 

 behind antennae. Antennae probably 13 segmented in major, 12 segmented in minor soldier. 



There is no doubt that these specimens belong to a new genus of some phylo- 

 genetic importance, being close to but more primitive than Trinervitermes, and 

 possibly even ancestral to it. The distinguishing features given in the diagnosis 

 have much in common with the Neotropical genus Diversitermes and it appears 

 most probable that Trinervitermes arose from this branch of the hypothetical 

 phylogenetic tree in which Ahmad (1950) placed V elocitermes , Tenuirostritermes, and 

 Ceylonitermes, and to which I (Sands, 1957) added Coarctotermes sensu lat. (Fulleri- 

 termes, Rhadinotermes, and Coarctotermes s. str.). At least 3 of these genera have 

 become adapted to grass feeding and two to grass storage convergently with 

 Trinervitermes, occupying equivalent ecological niches in their respective zoogeo- 

 graphical areas (Neotropical, Ethiopian, and Malagasy). Other genera of similar 

 habits and appearance from the Australian region have not been studied in detail 

 but may also be related. 



Mycterotermes is unlikely to be confused with any genus other than Trinervitermes 

 in the area covered by this revision. Its occurrence in Western Aden brings it into 

 the Ethiopian Zoogeographical Region. 



Mycterotermes meringocephalus sp. n. 



(Text-figs. 388-395 ; Map 3) 



Imago. Unknown. 



Soldiers. Major ; Head capsule orange-yellow, nose ferruginous. Antennae yellow, 

 pronotum and abdominal tergites yellow-brown. Abdominal sternites and legs pale yellow. 



Head capsule in plan view tapering slightly towards front, sides slightly sinuate behind 

 antennae, posteriorly weakly sulcate in mid-line, nose cylindrical to near base. In profile level 

 from tip of nose to downward curve at back of head, with slight hump at base of nose and very 

 weak constriction behind antennae ; nose distinctly shorter than rest of head capsule, measuring 

 from hind margin of antennal socket. Antennae, broken, II and IV subequal and shorter than 

 V, III nearly twice as long as II. 



Abdominal tergites with sparse fine minute setae, sternites with sparse shorter setae and longer 

 setae on posterior margins. 



Minor ; as major soldier except antennae, II shorter than III, IV, and V which are subequal. 



Remaining characters given in generic diagnosis. 



Measurements (Unique holotype major soldier, 2 minor soldiers). 



Major soldier Minor soldiers 



Head length to tip of nose 163 . . . . 1-22 



Head width . . . 1 -oo .... °'54 



Depth of head capsule . 0-59 .... 038 



