448 SERRICOBNIA. 



SPHENISCOSOMUS. 



Spheniscosomus, Schwarz, Wien. ent. Zeit. xi. p. 132 (1892) ; Buysson, Faune Gallo-Rhenane, Elat. 



p. 129 (1894). 

 Melanotopsis, Lewis, Ann. & Mag. Nat. Hist. (6) xiii. pp. 191, 192, figg. 1, 2 (1894). 

 Melanotics, Candeze, Monogr. Elat. iii. p. 298 (part.). 



Spheniscosomus includes those members of the old genus Melanotus which have the 

 prosternal process horizontally produced and the sides of the mesosternal cavity raised 

 and V-shaped. Seven species have been referred to it, including two from Southern 

 Europe, two from Japan, one from China, and two from Java * ; and six Tropical- 

 American forms must also be included. The genus has a more southern distribution 

 in the New World than Melanotus, extending as far south as Panama. The species, 

 like those of Melanotus, are very closely allied and not easy to separate. Some of them 

 have an additional carina or plica within the hind angles of the thorax ; this carina, 

 however, is not always distinct in the same species (it being often obsolete in the 

 females), and it cannot be relied upon as a specific character. The males, as in 

 Melanotus, usually have the antennae closely ciliate along their inner edge, and some- 

 times the fifth ventral segment is peculiarly sculptured in this sex, as, for example, in 

 S. tropicalis. S. Icevis is easily recognizable by the very deep, long basal sulci of the 

 thorax. The six Central- American species may be tabulated thus : — 



a. Antennae with the third joint short, not much longer than the second. 



a!. The hind angles of the prothorax with a long, sharp, oblique carina ; the basal 



sulci long and shallow; the prothoracic punctuation coarse and close . . . rubicundus. 



V. The hind angles of the prothorax with a sharp, straight carina ; the basal sulci 



short, the prothoracic punctuation excessively coarse and moderately close . lanuginosus. 



b. Antennae with the third joint much longer than the second. 

 c'. Hind angles of the prothorax with a long, sharp carina. 



a". The basal sulci long ; the prothoracic punctuation very sparse and rather 



tine; body elongate tropicalis. 



b". The basal sulci short; the prothoracic punctuation closer and very coarse; 



body rather short cribrosus. 



d'. Hind angles of the prothorax obsoletely carinate ; body elongate. 



c". The basal sulci moderately long, shallow in front ; the prothoracic punctua- 

 tion coarse, sparse rodriguezi. 



d". The basal sulci long and very deep; the prothoracic punctuation fine, very 



sparse la>vis. 



1. SphenisCOSOniUS rubicundus. (Tab. XX. figg. 4, 6; 4 a, prothorax.) 

 Melanotus rubicundus, Caud. Ann. Soc. Ent. Belg. 1889, p. 112 (Elat. Nouv. iv. p. 46) \ 



Hab. Guatemala 1 , Capetillo (Champion). 



One female and two males of this species were captured by myself in Guatemala. 



* Melanotus ebeninus, Cand., from Luzon, and M. cuneolus, Cand., from Java, also belong to Spheniscosomus. 



