PROC ENT. SOC. WASH., VOL. 22, NO. I, JAN., IQ2O 7 



extended from prothorax, epignathous; labrum present; mouth parts deeply 

 retracted, fleshy; cardo large, cushioned; maxillary sclerite distinctly cush- 

 . ioned; ligula long, obtusely conical and exceeding in length the labial palpi; 

 gula elongate, thinly chitinized mandibles without molar structure, apex 

 bidentate, retinaculum present; antennae contiguous to mouth frame, two- 

 or-three- jointed, the basal joint bearing a large dilated supplementary joint; 

 no thoracic hypopleural chitinization; presternum of prothorax triangular; 

 presternal fold of mesothorax and metathorax very broad; cerci, when 

 present, of two recurved spines; ninth abdominal segment terminal; tenth 

 wart-like; spiracles annuliform, mesothoracic, on presternal ring. 



TAXONOMIC POSITION OF THE BOTHRIDERIDAE.' 



The relationships of this family are problematical. As stated 

 in the introduction they are certainly quite distinct from any of 

 the Colydiidae here described. The peculiar form and habits 

 tend to emphasize this distinction, possibly too emphatically- 

 and give a suggestion of Clerid or Trogositid affinities. For the 

 present, however, it is probably more natural to regard them as 

 a specialized development from some of the Colydids with reduced 

 molar structure. The parasitic nature of these larvae does not 

 necessarily demand a morphological change of the fundamental 

 head structures. This is well illustrated by the parasitic genera 

 placed in the Cucujidae, Catogenus and Scalidia, where we find 

 identical form and habits but radically different head structures. 



Description of the Larva and Pupa. 

 Deretaphrus oregonensis Horn. 



Larva. Fleshy, fusiform, widest about 5th and 6th abdominal segments; 

 integument thin, practically glabrous; maximum length 14 mm. 



Head subglobular, epignathous, extended; occipital foramen posterior; epi- 

 cranial halves ventrally separated by thin sub-rectangular gular region; 

 ventral mouth parts retracted; clypeus and labrum distinct, both roundly 

 transverse, latter twice as wide as long, having anterior margin sinuate; no 

 frontal or epicranial sutures; antennae laterally inserted; very small, two- 

 or-three- jointed, basal joints bearing a long, distinact appendage, 2d and 

 3d joints subequal; no ocelli; mandible triangular, without molar structure, 

 bifid at apex and having a large retinaculum; ventral mouth parts fleshy, 

 weak, retracted about half the depth of the head; margins of hypostoma 

 slightly chitinized, maxillary sclerite distinct, cushioned; cardo large, fleshy, 

 with a triangular chitinization; inner margin of stipes chitinized; lacinia 

 broad, fleshy; no galea; maxillary palpi three-jointed; 3d joint longest; no 

 palpifer; submentum large trapezoidal; mentum barrel-shaped; ligula long, 

 conical, greatly exceeding labial palpi; palpi two-jointed. 



1 The following taxonomic discussion is based on a joint study of the 

 characterization of Coleopterous larvae undertaken by A. G. Boving and 

 F. C. Craighead. 



