150 PROC. ENT. SOC. WASH., VOL. 24, NO. 6, JUXE, 1922 



labellum and curving back to between the front coxae. The 

 epipharyngeal prongs are also well developed, forming two 

 decurved tusks extending beyond the labrum. 



In Langhoffer's second group, including genera similar to 

 Dolichopus, the epipharyngeal armature is less developed and 

 consists of two ventral, longitudinal ridges beneath the labrum, 

 ending anteriorly in free points. In the next two groups, 

 including a smaller number of genera, Porphyrops, Neurigona 

 and Orthochile, the armature is still weaker. In all four groups 

 the presence and position of spines and teeth on the lobes con- 

 stitute also distinguishing characters. 



It is evident that Langhoffer was not acquainted with species 

 having the characters of Melanderia, else he would have had to 

 define a fifth group to include forms having four well-developed 

 epipharyngeal prongs. In this he was fortunate, however, for 

 such a discovery might have embarrassed his mandible theory. 



Melanderia mandibulata does not stand alone as a unique 

 thing; it culminates a small series of forms tending toward an 

 excessive development of mouth armature, all of which live 

 along ocean beaches where they probably feed on small animals 

 stranded by the tide, as do other members of the family. We 

 may suppose that their mouth hooks and prongs give them a 

 special efficiency in ripping open the soft skin of the creatures 

 from which they then suck out the body fluids. Dr. Aldrich, 

 who has furnished the material for this paper, describes how he 

 has seen shore-inhabiting species of Do/ichopus, with the pro- 

 boscis attached to one end of living prey, apparently sucking 

 the b'ood, undisturbed by the squirming and writhing of the 

 victim. 



Hypocharassus pruinosus, from the beaches of Florida, 

 Georgia and North Carolina, has an epipharyngeal armature of 

 four thick, wide pieces, the anterior plates being especially deep 

 and provided on the front edges with a series of small teeth 

 above the principal hooks. This apparatus constitutes a 

 lacerating implement probably quite as effective as the epi- 

 pharyngeal parts of Melanderia. But this species has no labial 

 "mandibles," though the general outlines of the lateral lobes of 

 the labellum are very suggestive of those of Melanderia when 

 its jaws are closed (fig. 2). 



Melanderia curvipes, of the coast of Southern California, is 

 distinctly of the mandibulata type. It was formerly placed 

 in the genus Hydrophorus, but Dr. Aldrich would now transfer 

 it to Melanderia. The labellum on each side is separated into 

 a dorsal and a ventral division, and the tip of the lower one is 

 prolonged and curved inward as a strongly chitinous, polished 

 lobe, but with a rounded edge instead of a sharp point. The 

 epipharyngeal armature is like that of mandibulata, but the 

 plate (x) at the base of the labium, on which the epipharyngeal 



