the Family Cichlidae. 39 



cycloid, large (32-34); two lateral lines. Mouth terminal ; 

 teetli very slender, triciis[)id, in broad bands. Lower 

 pharyngeal with long anterior blade ; dentigerous area 

 broadly heart-shaped ; teetli small, slender, numerous. 

 Occipital and parietal crests extending forward nearly to 

 anterior end of frontals ; parietal ci'ests mid-way between 

 occij>ital crest' and orbital margin; ethmoid well separated 

 from vomer ; nasal bones strongly expanded posteriorly; 

 posterior part of parasphenoid raised, bearing a pair of 

 near!}'' circular facets for articulation of upper pharyngeals. 

 Vertebra; 31 (17-f-14:); inferior apophyses of third united 

 below to form a strong spine. 



Tanganyika ; two species. 



The resemblance in external characters to T. nilotlca and 

 T. galilcea extends to every detail of the skeleton. 



4. LiMNOTlLAriA, gen. nov. 

 (type Tilapia dardennli, 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 ; maxiUary not exposed ; jaws with an 

 outer series of teeth, all bicuspid or some conical, and one or 

 more inner 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; prsemaxillary processes slender, 

 about reacliing anterior edge of frontals ; maxillary siiort 

 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. Vertebrse 

 33 or 34 (16-17 + 17) ; third with a pair of inferior apophyses 

 which meet below, but do not unite; prascaudals with para- 

 pophyses from the fourth ; each of the last three pairs 

 connected by a bridge ; ribs, except the first, on parapo- 

 pliyses. 



Tanganyika. 



Three s\)e(.'.ie!i{L.darden)iii,pleurol(enia, and trematocepJiala) . 

 Very close to Tilapia, dilfering especially in the form of the 

 nasal bones and pra3maxillary processes and tiie structure of 

 the inferior apophyses of the third vertebra ; of tiie species 



