680 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 47. 



Specific characters of the female. — Cephalothorax longer than tlio 

 trunk and very slender; head not enlarged but tapered strongly 

 anteriorly; no dorsal carapace; trunk pear-shaped, somewhat flat- 

 tened dorso-ventrally, narrowed mto a short neck anteriorly where it 

 joins the cephalothorax, and with two posterior knobs, one at the 

 mouth of each oviduct; no genital process. 



First antennae pointing ventrally and apparently two-jointed, 

 the terminal joint very small and tipped with three setae; second 

 anteim.ae uniramose, three-jointed, the two terminal joints turned 

 down across the frontal margin and tapered to a point. The ante- 

 rior margin of the head is so narrow and these antennae are so long 

 that they overlap considerably at the midline. Mouth tube a 

 broad cone, so short that it reaches only halfway to the second 

 antennae; first maxillae bipartite at the tip, with a rudimentary 

 palp, tipped with a single seta; second maxillae fused for their 

 entire length, but with the line of demarcation plainly visible. 

 Each maxilla is considerably swollen and bears at the tip and on the 

 sides chitin scales, which point backward, away from the tip, and 

 overlap one another like shingles. Bulla small, dark-colored, and 

 club-shaped; maxillipeds with a narrow and elongate basal joint 

 and a medium terminal claw, reenforced with an accessory spine on 

 the inner margin near the center. 



Cephalothorax, 6 mm. long, 0.4 mm. wide. Trunk, 4.66 mm. 

 long, 2 mm. wide, 1 mm. thick. 



{squamigera, squama, a scale, and gero, to bear, alluding to the 

 remarkable scales on the second maxillae.) 



RemarTcs. — This species can be recognized at once by the scales 

 on the second maxillae, since nothing like them has been reported 

 from any other species. They seem to increase both in size and in 

 number with the age of the parasite. They bear some resemblance 

 to the anchoring apparatus found on the heads of some of the Ler- 

 naeidae. But in the present instance they do not even touch the 

 skin of the host, to say nothing of being buried in its flesh, since 

 there is a normally functioning bulla at the tips of these maxillae. 

 Their use is decidedly problematical. 



CLAVELLA UNCINATA (MUller). 



Plate 27, fig. M; plate 48, figs. 167 to 173; plate 49, figa. 174 to 176. 



Lernaeaundnata Mij-LhER, 1776, p. 38, pi. 33, fig. 2. 



Schisturus uncinatus Oken, 1815, p. 183. 



Clavella uncinata Oken, 1815, p. 358. 



Lernaeomyzon uncinata Blainville, 1822, p. 438. 



Clavella uncinata Cuvier (Oken), 1830, p. 258. 



Ancorella uncinata Nordmann, 1832, p. 102. 



Anchorella uncinata Kr0yer, 1837, p. 193, pi. 3, fig. 8, a to/. 



