168 LAMELLICOKNIA. 



This species is labelled Liogenys angustata, Chevr. (MS.), in the Salle collection ; the 

 specific name I cannot adopt, as it would be very inappropriate in the genus to which 

 the insect really belongs. The tarsi are shorter and the joints much broader than in 

 C. cegrota, joints 2-4 being more than half as broad as long. There is no rudiment of 

 a third (upper) tooth on the anterior tibise in the male, which is perceptible in the 

 other species, and only a slight indication of it in the female. 



4. ChlsBiiobia tumulosa. 



C. cegrotm similis et afflnissima : differt thorace angulis posticis exstantibus acutis ; pygidio utroque sexa 



mediocriter discrete punctato, apice solum piloso. Antennae 10-articulata3. 

 <S . Tarsi lineares, sed articulis quam in G. cegrota paullo latiores. Venter medio planatus subconcavus, 



segmentis 2°-4 m dense brevior pilosis, 5° et 6° scopiferis. 

 5 . Pygidium post medium oblique valide bituberosum, apice profundissime concavo, margine apicali medio 



sinuato ; lamina ventrali segmentum ventrale 7 m simulante. 

 Long. 14-17 millim. 



Hab. British Honduras, E. Sarstoon (Blancaneam) ; Guatemala (Salle), near the 

 city, Duenas, Capetillo (Champion). 



The anterior tibiae in the male have a slight indication of a third tooth, and in the 

 female are more distinctly tridentate. 



A single example (female) from Guatemala city has simply an irregular cavity on 

 the pygidium. It is apparently deformed. 



5. Chlaenobia bicallosa. 



C. tumulosce proxime affinis : differt thorace fortius punctato, magis rotundato et postice magis angustato, 



angulis posticis acutis sed minus exstantibus. 

 $ . Pygidium medio fere usque ad basin sulcatum, apice baud excavatum, tuberibus medianis conicis minus 



obliquis, margine apicali rotundato, reflexo ; lamina ventrali nulla. Antenna? 10-articulatse. 

 Long. 15 millim. 



Hab. Mexico, Tomatlan, Tuxtla (Salle). 



Three female examples only. The very different structure of the pygidium, which 

 has no ventral horny plate simulating a seventh ventral segment, supported as this 

 character is by the somewhat smaller, more rounded, and more coarsely punctured 

 thorax, justifies the separation of this insect from C. tumulosa. 



The striking modifications in the secondary sexual characters, in closely-allied forms 

 of this genus, forms which other circumstances indicate to be only local varieties, are 

 of great physiological significance. 



6. ChlaBnobia sequata. 



Prsecedentibus simillima, paullo minor ; clypeo minus ampliato, lateribus rotundato-convergentibus ; thorace 



disperse punctato, angulis posticis acutis. 

 3 . Pygidium convexum, sparse punctatum, margine apicali rotundato-reflexo ; ventris segmenta 5 m et 6 m medio 



longe fascieulatim, 2°-5 m brevius, pilosa ; tarsi crasse filiformes, parum dilatati, subtus dense pilosi ; tibiarum 



