7 6 COLEOPTERA 



FAMILY GYRINIDES. 



Mentum deeply emarginate. Ligula horny, prominent. Maxilla 

 slender, arched, very acute, nearly always without external lobe. Palpi 

 short ; the labial with three, the maxillary with four joints. Mandibles 

 short, arcuated, and bi-dentate at their extremity. Two eyes on each 

 side, one above the other. Antenna very short, robust, rigid, eleven- 

 jointed ; the second and third joints large ; the latter externally pro- 

 longed in the form of a lobe ; the terminal longer than the seven pre- 

 ceding joints united, which are very short. The four hind legs strongly 

 compressed and very wide ; posterior coxae prolonged posteriorly ; the 

 tarsi five-jointed. Abdomen composed of six segments ; the first three 

 connate. 



Gyrinus. 



Geoffr. ; Lacord. Hist, des Ins. Coleop., Tom. \.,p. 438. 



Mentum without middle tooth. Jaws furnished with an external 

 lobe. Last joint of the palpi longer than the preceding united. Labrum 

 transversal, rounded and ciliated in front. Epistome short. Scutellum 

 distinct, usually elongated and acute behind. Elytra oval or oblong, 

 rounded or truncated, but seldom hollowed behind, moderately convex. 

 Anterior legs moderate, their tarsi elongated among the males, rather 

 narrow and sponge-like beneath. Last abdominal segment depressed, 

 rounded at the end, in general scarcely, or not at all, ciliated. 



Body oviform, oblong, more or less convex. 



142- Gr. hllttoni, Pascoe, Ann. Mag. Nat. Hist., February, 1877. 

 G. obovatus, niger, nitidus ; prothorace longitudine quam latitudine 

 quadruple minore ; scutello elongato-triangulari ; elytris lineatim punctu- 

 latis ; sutura senea ; pedibus antennisque rufo-testaceis. 



Long., 2 lin. 



Waikato. 



Rather larger than our G. minutus, the anterior half broader than 

 the posterior half, and the prothorax very considerably longer (the 

 breadth is above six times the length in G. minutus) ; and its scutellar 

 lobe is very transverse. My specimen has a slight iridescent hue. This 

 and other species from Waikato and Otago have been kindly sent to 

 me by Captain Hutton. 



FAMILY PALPICORNES. 



Mentum large, entire. Maxilla terminated by two unarmed lobes. 

 Maxillary palpi generally long, sometimes longer than the antennae. 

 Mandibles very short. Antenna with six or nine joints; the first always 

 elongate, the last forming a club. The posterior legs natatorial among 

 a certain number; tarsi five-jointed. Abdomen composed of five, rarely 

 of four, six, or seven segments. 



