688 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xx. 



tome triangular, bounded behind by a transverse furrow, apex sub- 

 acute. Basal segment of antenna devoid of spines, neither is there 

 any trace of an external spine at the base of the antennal scale; the 

 latter is small, broad, its inner border rounded, its outer border termi- 

 nating in a long, stout, straight tooth or spine. Third maxillipeds 

 hairy within. Chelipeds long, usually symmetrical on the two sides of 

 the body, but in some individuals distinctly unsymmetrical ; upper 

 margin of merus lightly serrate, without any prominent tooth; lower 

 margins armed with a row of small, blunt teeth or tubercles, lower 

 face more or less tuberculous, inner and outer faces smooth ; carpus 

 short, triangular, superior internal margin with a series of small obso- 

 lescent teeth or tubercles; there is also a short row of similar teeth 

 near the external lower angle of the carpus, near the point of articula- 

 tion with the chela; chela large and powerful, palm inflated, outer and 

 inner faces smooth, superior margin nearly straight, adorned with low, 

 squamous tubercles which are irregularly disposed in two rows; the 

 inferior margin of the hand is convex, and is similarly ornamented with 

 biserial, depressed obsolescent tubercles which cease at the base of the 

 immobile finger. The fingers are conspicuously marked with longitudi- 

 nal rows of pits, three rows on each finger; the cutting edges are 

 irregularly toothed, two teeth on the movable finger and three on the 

 immovable finger; the fingers are not conspicuously bearded. The 

 median carina of the inner branch of the posterior pair of abdominal 

 appendages ends near the hind margin without developing a spine. 



Dimensions of a specimen: Length 96 mm.; carapace 48 mm.; from 

 tip of rostrum to cervical groove 32 mm.; from cervical groove to pos- 

 terior border of carapace 1 5.5 mm. ; width of areola 4.5 mm. ; length 

 of cheliped 86 mm.; length of merus 22 mm.; length of carpus 17 

 mm.; breadth of carpus 13 mm.; length of chela 39.5 mm.; breadth 

 of chela 18 mm.; length of dactylus 25 mm. 



In the number and arrangement of the brauchial organs, Parasiticus 

 hassleri agrees with P. varicosus. 1 The epipod of the first maxilliped 

 bears gill filaments, as in the latter species, the podobranchite have 

 narrow alae, the posterior arthrobranchia of the thirteenth somite is 

 reduced to a small filament which bears a single lateral branch. The 

 coxopoditic setse are long and hooked at the end. 



Habitat. — Talcahuano, Chile, No. 3401, Coll. Mus.Comp. Zool., (Hassler 

 Exped., April, 1872). One hundred specimens. 



Astacus ehilensis Milne-Edwards, 2 from "the coast of Chile," is not 

 described with enough detail to be determinable. The type, however, 

 may be still extant in Paris. It is said to bear a close resemblance to 

 Astacus australasiensis Milne- Ed wards, 3 but to differ from the latter 

 species in having a shorter rostrum, a carpus destitute of teeth or 



'Page 685. 



*Hist. Nat. des Crustac^s, II, p. 333, 1837. 



3 Ibid., II, p. 332, pi. xxiv, figs. 1-5, 1837. 



