534 CANAEIAN COLEOPTERA. 



tremely long), combined with its posteriorly attenuated abdomen, its 

 oval head and large eyes, its subquadrate prothorax, and its most 

 minutely (though densely) punctulated surface, will sufficiently dis- 

 tinguish it. Like the Chiloporce, it is of subaqiiatic habits — as indeed 

 its general structure and rapid movements would seem to indicate. 



801. Tachyusa simillima, n. sp. 



T. depressa, fuseo-nigra, subnitida, densissime punctulata, dense ci- 

 nereo-pubescens ; capite quadrate, in fronte longitudinaliter im- 

 presso, oculis parvis ; prothorace late canalieulato ; elytris vix fus- 

 cescentioribus ; abdominc nigro ; antennis j)edibusque infuscato- 

 testaceis. — Long. corp. lin. 1. 



Ohs. — Species T. sulcake Kiesenw. nimis affinis, et forsan ejus 

 varietas geographica. Differt solum corpore subminore, subangus- 

 tiore, elytris subminoribus, punctiu'a (praesertim in capite) sensun 

 fortiore necnon colore dilutiore (sc. magis fuscescente, antennis pe- 

 dibusque pallidioribus). 



Habitat Lanzarotam et Fuerteventuram, sub fucis per eras arenosas 

 maritimas degens. 



I am doubtful whether this Tacliijusa should be regarded as more 

 than a geographical modification of the European T. sulcata ; never- 

 theless, since it unquestionably has a few differential features of its 

 own, and as the acknowledged distinctions between the species of this 

 immediate type are very minute, I do not think it should be absolutely 

 identified with that insect*. It seems to be altogether a trifle smaller 

 and narrower than the sulcata, with its elytra somewhat less deve- 

 loped ; its punctation (particularly on the head) is a little stronger, 

 and its colour is less black — the head, prothorax, and elytra being 

 appreciably browner and the Hmbs more testaceous. From the Ma- 

 deiran T. maritima it is abundantly distinct — not merely in its much 

 smaller size and narrower outline, but likewise in its browner hue, its 

 flatter and more sulcated head, and its thicker antennae (the joints of 

 which are less elongated, or more moniliform). The only two speci- 

 mens which I have seen were taken by myself (from under sea-weed) 

 on the sandy shores of Lanzarote and Fuerieventura respectively, — 

 namely, to the south of Arrecife of the former and of Puerto de Ca- 

 bras of the latter. 



Genus 304. XENOMMAt. 

 Wollaston, Ins. Mad. 54:3 (1854). 



* Dr. Kraatz, to whom I sent one of my specimens for examination, returned 

 it with tlie remark " Tachyusce sidcatce Kiesenw. affinis, sed minor, capite fortius 

 punctato." 



t Whether Xenomma can be retained as a distinct genus, I will not venture to 



