372 PERCY SLADEN TRUST EXPEDITION 



21. Pison (Parapison) isolatum, sp. n. 



?^. Niger, punctatus, abdornine nitido, pedibus, tegulis, scapo et flagello basi rufo- 

 ferrugineis. 



$. Clypeus nearly twice as broad as long, finely punctured, produced and narrowly 

 rounded on the middle of the apical margin. Head opaque, obscurely punctured, a carina 

 from the base of the clypeus reaching half-way to the anterior ocellus. Second joint of 

 the flagellum distinctly longer than the third ; eyes separated on the vertex by a distance 

 about equal to twice the length of the thud joint of the flagellum ; the posterior ocelli 

 rather further from each other than from the eyes ; the emargination of the eyes rather 

 deep, the eyes are twice as far apart on the clypeus as on the vertex. Thorax finely and 

 rather sparsely punctured ; the median segment shorter than the mesonotum, narrowed 

 posteriorly, irregularly and indistinctly obliquely striated, with a median sulcus not quite 

 reaching the apex, the surface of the posterior truncation indistinctly transversely striated 

 with a deep median sulcus. Abdomen subpetiolate, smooth and shining, the first segment 

 longer than its breadth at the apex. First abscissa of the radius longer than the second ; 

 first recurrent nervure received close to the apex of the first cubital cell, second at one- 

 third from the base of the second (third) cubital cell. 



Black ; scape, four basal joints of the flagellum, mandibles in the middle, tegulse and 

 legs (except the coxae and the apical joint of the tarsi) ferruginous. Wings hyaline, 

 tinged with fuscous, nervures black. 



Length 8 mm. 



$ . Clypeus produced into a point on the middle of the apical margin ; apical dorsal 

 segment of the abdomen large, rounded at the apex. Otherwise as in the female. 



Localities. Seychelles : Silhouette, specimens settling on paths on plateau of Mare 

 aux Cochons, over 1000 ft., VIII— IX. 1908 : Mahe, Cascade Estate, about 1000 ft., III. 

 1909 (H. Scott). 



Genus Trypoxylon Latr. 



22. Trypoxylon errans Sauss. 



Trtjpoxylon errans Sauss., Reise Novara Zool. ii. Hym. p. 84, 1867. 

 Trypoxylon gardineri Cam., Trans. Linn. Soc, Ser. 2, Zool., xii. 1907, p. 76. 

 Localities. Mauritius (Saussure). Mahe\ Cascade Estate, November to March, and 

 Long Island, July (H. Scott). Coetivy, 1905 (J. Stanley Gardiner). 



" This species comes into rooms at Port Victoria and goes into nail holes in walls." 

 Species of Trypoxylon and Pison have similar habits in other countries, often forming 

 their nests in key-holes. 



Saussure gives the colour of the clypeus as yellow (Hist. Madagascar xx. p. 527, 

 1892) ; in the Seychelles the colour is black, but this is also the case in specimens from 

 Mauritius in the British Museum, and Saussure's original description only gives " Clypei 

 margo testaceus." 



