the Family Gichlidee. : 39 
eycloid, large (32-34); two lateral lines. Mouth terminal ; 
teeth very slender, tricuspid, in broad bands. Lower 
pharyngeal with long anterior blade ; dentigerous area 
broadly heart-shaped ; teeth small, slender, numerous. 
Occipital and parietal crests extending forward nearly to 
anterior end of frontals; parietal crests mid-way between 
occipital crest and orbital margin; ethmoid well separated 
from vomer ; nasal bones strongly expanded posteriorly ; 
posterior part of parasphenoid raised, bearing a pair of 
nearly circular facets for articulation of upper pharyngeals. 
Vertebree 31 (17+14); inferior apophyses of third united 
below to form a strong spine. 
Tanganyika ; two species. 
The resemblance in external characters to 7. nilotica and 
T. galilea extends to every detail of the skeleton. 
4, LIMNOTILAPIA, gen. nov. 
(type Tilapia dardennit, Bouleng.). 
Dorsal XV-XX 9-12. Anal III 8-10. Scales cycloid or 
finely denticulate, large (32-40) ; two lateral lines. Mouth 
terminal, rather small; maxillary not exposed ; jaws with an 
outer series of teeth, all bicuspid or some conical, and one or 
more ner series of small teeth, all tricuspid or some uni- 
cuspid in adult. Lower pharyngeal triangular, with slender 
uni- or bicuspid teeth; anterior blade short or moderate. 
Occipital crest extending forward to posterior end of a median 
anterior excavation of frontals ; parietal crests ending above 
posterior part or middle of orbits, at or near orbital margin ; 
mesethmoid suturally united with vomer: nasal bones mode- 
rately expanded posteriorly ; preemaxillary processes slender, 
about reaching anterior edge of frontals; maxillary short 
and broad, with a large rounded expansion below palatine 
articulation ; rami of lower jaw with straight inner edges ; 
posterior part of parasphenoid slightly raised, bearing a pair 
of facets for articulation of upper pharyngeals. Vertebre 
33 or 34 (16-17 +17); third with a pair of inferior apophyses 
which meet below, but do not unite; preecaudals with para- 
pophyses from the fourth ; each of the last three pairs 
connected by a bridge; ribs, except the first, on parapo- 
physes. 
‘Tanganyika. 
_Three species (Z.dardennii, pleurotenia, and trematocephala). 
Very close to Tilapia, differing especially in the form of the 
nasal bones and preemaxillary processes and the structure of 
the inferior apophyses of the third vertebra; of the species 
