6 ADEPHAGA. 
yellow marks on them are also variable; the external margin is yellow, and has con- 
nected with it about the middle a more or less obsolete small mark ; at the base between | 
the suture and the shoulder there is a stripe extending about half the length of the 
wing-case, and just behind the middle, nearer the suture, an indistinct short vitta: these 
markings, however, are sometimes much reduced in size. The punctuation of the elytra 
is rather deep and distinct, but is somewhat variable in these respects ; no serial punc- 
tures can be detected. The prosternal process is not canaliculate. The male has the 
basal joint of the front and middle tarsi a good deal incrassate; the female has the 
extremity of the last ventral plate obscurely plicate in the middle. 
3. Canthydrus subsignatus. 
Canthydrus subsignatus, Sharp, Trans. Roy. Dubl. Soc. n. s. ii. p. 271. 
Hab. PANAMA. 
This is very closely allied to C. varians, but is larger and broader, and the structure 
of the last ventral segment in the female (the only sex known) appears to be different. 
4, Canthydrus centralis. 
Canthydrus centralis, Sharp, Trans. Roy. Dubl. Soc. n. s. ii. p. 274. 
Hab. GuateMaLa, San Gerénimo, Guatemala city, 5000 feet (Champion). 
5. Canthydrus majusculus. 
Ovalis, latiusculus, testaceus, elytris sordidis, superne in thorace et in elytris fortiter irregulariter punctatus ; 
coxarum laminis externis parum coriaceis, internis fortiter punctatis. 
Long. 13, lat. 1 lin. 
Hab. Panama, David (Champion). 
This species is of larger size than any other yet known of the genus, and this, in 
combination with the distinctly punctate upper surface, permits its easy identification. 
The prosternal process is depressed along the middle, and the raised coxal lamine and 
middle of the metasternum are very closely punctate; on the other hand, the sides of 
the breast are almost smooth. The swimming-legs are rather thicker than usual in the 
genus. The two individuals before me are probably males; the apical ventral segment 
is quite without impressions. The terminal five joints of the antenne are a little 
irregular, the seventh joint being distinctly longer than either of the following three, 
while the eighth and tenth are each distinctly smaller than the adjacent joints. 
6. Canthydrus mexicanus. (Tab. I. fig. 4.) 
Hydrocanthus lineatus, Wehncke, Berl. Zeit. xx. p. 221. 
Hab. Mexico, Cordova (Sallé), Oaxaca (Hége). 
This is very closely allied to C. centralis, but is larger and of brighter colour, the 
