INSECTA MADERENSIA. 71 



evanescent towards the outer margin. It is the only Trechns which I have 

 hitherto observed in any of the other islands of the group; being apparently 

 peculiar to Porto Santo, where, dviring the winter and early spring, I have ob- 

 served it in tolerable abundance, beneath stones, on the grassy mountain- slopes at 

 an elevation of about 900 feet above the sea, — though especially on the green 

 exposed ridge which connects the Pico de Faclio with the Pico do Oastello. 



Genus 23. THALASSOPHILUS, Wall. (Tab. II. fig. 5.) 



Corpus parvum, lineare : prothorace cordato : alis obsoletis. Antenme filiformes, capite prothoraceque 

 multo longiores, articulo ])rimo sequentibus robustiore, secundo breviusculo, reliquis sub- 

 aequalibiis. Lahrum (II. 5 a) transvei'sum, antice profunde emarginatum, aut potius bilobum, 

 lobo quoque apice barbato et setis paucis longissimis instructo. Mandibulee (II. 5 b, o c) longse 

 porrectse acutae, intus basi denticulate. Maxilla (II. 5 d) bilobse : lobo externa palpifonni 

 biai'ticulato : interno acuto iucurvo, apice uuciuato, intus valde ciliato. Palpi articulo ultimo 

 penultimo minore, in maxillaribus eonico, in labiulibus (II. 5 e) subfusiformi-conico. Mentum 

 transversum, antice profunda emarginatum et dente medio brevi bifido instructum. Ligula 

 brevis subcornea, apice rotundata pilisque longissimis ornata; paraglossis angustis linearibus, 

 cam superantibus. Pedes robusti : tarsis anticis in maribus (II. 5 /) articulis primo et secundo 

 dilatatis atque intus productis : unguiculis simplicibus. 



A OaXaaaa mare, et ^tXo? amicus. 



The very interesting insect for which the present genus has been established 

 approaches slightly, in its outward appearance, to the Cillenum laterale of oui- owti 

 country ; nevertheless the large terminal joint of its palpi wiU of com-se remove it 

 from the whole section of the Bembidiudes, whilst from that species in particular the 

 bifid central tooth of its mentum and deeply bilobed upper lip, in conjimction with 

 its elongated antennae (which have the foui-th joint not shorter than the pre^dous one) 

 and the peculiar dilation of its male tarsi, will serve additionally to distinguish 

 it. In the proportions of its palpi indeed, and of its upper Hp, as well as in its 

 freedom from Avings, ThalassopUlus is perhaps more nearly related to Aepus than 

 to anything else with which I am acquamted. StiU, its comparatively gigantic 

 size and dissimilar form, added to the bifid tooth of its mentum, will readily 

 separate it from that genus also : and it may not inappropriately be regarded as 

 constituting a passage between the Hmyalldes and the Bembidiades, — for whilst 

 the greatly developed ultunate joint of its palpi must needs place it amongst the 

 former, yet its general habits and aspect are so intimately allied to some of the 

 early members of the latter as to render its affinity with them Likewise scarcely 

 less obvious. 



55. Thalassophilus WMtei, Woll. (Tab. II. fig. 5.) 

 T. rufo-ferrugineus nitidus depressus, capite picescenti, prothorace cordato lateribus postice sub- 



