100 HYDROPHILID A. 
6. Phenonotum rotundulum. (Tab. III. fig. 9.) 
Subrotundatum, convexum, nigro-piceum, nitidissimum, prothoracis marginibus capiteque anterius picescen- 
tibus, subtus piceo, capite prosternoque rufis; tarsis, palpis antennisque basi testaceis, harum elava fusco- 
testacea ; capite thoraceque fere omnino impunctatis, elytris sparsim punctatis, punctis ad basin subtili- 
oribus, minutis. 
Long. 14, lat. 1 lin. 
Hab. Mexico, Cordova, Toxpam (Sadlé); Guatema.a, San Gerénimo, Chacoj, San 
Juan and San Joaquin, Zapote, El Tumbador 2500 feet (Champion); Panama, Volcan 
~ de Chiriqui, 4000 to 6000 feet (Champion). 
Of all the species this is the shortest and most rotund in form, and has the least 
punctuation of the upper surface; the head is more dilute in colour in front than it is 
in any of the other species, and this appears to be always the case, though sometimes 
not very conspicuously. The diminished punctuation allows the species to be readily 
enough distinguished from P. levicolle, which is nearest to it in size and form. 
CYCLOTYPUS. 
Corpus hemisphericum, supra nitidum, subtus subtilissime pubescens, opacum. Antenne sat elongate, 
articulis intermediis haud transversis, clava laxissime articulata. Oris partibus dense hirsutis, mento 
anterius leviter impresso, palpis maxillaribus sat gracilibus, quam antenne multo brevioribus. Prosternum 
ante coxas simplex, haud perbreve. Mesosternum ante coxas rhomboidale. Metasternum anterius inter 
coxas productum, sed haud longitudinaliter elevatum, sutura cum mesosterno haud consolidata, depressa. 
Pedes sat elongati. Tarsi omnes quinquearticulati, subtus hirsuti, intermediis et posterioribus articulo 
basali majore, incrassato, duorum sequentium longitudine. 
This genus is established for two species differing in several points from the other 
allied genera, more especially in the structure of the sternal pieces along the median 
line. The front portion of the prosternum is very acuminate in the middle behind, but 
the point does not form a free projection, but is met by the lamina between the two coxal 
cavities, and this lamina behind forms a small emarginate process. The metasternum 
is connected in the middle in a comparatively only imperfect manner with the meso- 
sternum ; it is distinctly, though not greatly, produced in front, but is not elevated; the 
point of connexion with the mesosternum forms, indeed, a depression ; the central piece 
of the mesosternum is rather large, and forms an angle in front, the two divergent sides 
being strongly margined ; posteriorly it is produced backwards between the coxee, so 
that it is thus of irregular rhomboidal form. ‘The basal ventral plate is not carinate. 
Although the facies is very different from that of Cyclonotum proper, it is apparently 
that genus, and not Phenonotum, that most approximates to Cyclotypus. 
1. Cyclotypus godmani. (Tab. III. fig. 10.) 
Subhemisphericus, supra niger, nitidus, subtus piceus, pedibus rufis; antennis palpisque testaceis, illarum 
clava leviter infuscata; capite crebre sat fortiter punctato, prothorace valde transverso, nitidissimo, 
