10 Strtt€ture of some of the Organs of a Spider, 



See, in Vol. V. p. 473., a notice of the occurrence of " vast 

 flocks of teal" in Jamaica, during the cooler months. They 

 are, the writer states, " of the species, I apprehend, named by 

 Gmelin the carolindnsis, or American teal." — J, D, 



Art. III. An Illustration of the Structure of some of the Organs 

 of a Spider, deemed the Type of a new Genus, and proposed 

 to be called Trichopus libratus. By C. M. 



[" Contrivance intricate express'd with ease. 

 Where unassisted sight no beauty sees." 



Cowper's Retirement.'] 



Sir, 

 I MISTOOK the spider of which I send you a sketch for 

 Pholcus jphalangioides, which I had never met with living. 

 The great length of its legs, the cylindric body (fg, 3. q), and 

 the attitude, caused it to bear so considerable a resem- 

 blance to that species, that it was only on carefully examin- 

 ing the eyes and parts of manducation, that I discovered 

 my" error. As it agrees exactly with none of the heretofore 

 established genera, I propose naming it 



Tri'chopus. (Thrix, hair, pons, foot; legs extremely hairy, the hairs 

 themselves branched, n.) Eyes 8, large, subequal, separated by a con- 

 siderable interval from the base of the mandibles ; placed in two rows, the 

 anterior curving considerably downwards and having the eyes approximated, 

 the posterior curving forwards and having the eyes widely separated, the 

 exterior being placed on a species of tubercle {fig. 3. a b). Mandibles 

 cylindric, cut off very obliquely beyond the middle of their inner side, and 

 presenting a cavity toothed on both sides for receiving the strong curved 

 hook ; hairy and spiny (c). Maxillce strong, rounded externally at the 

 apex, and cut off very abruptly internally, contracted behind the middle, 

 and dilated slightly where they receive the palpi (d). Lip higher than 

 broad, narrowed anteriorly, and with a sinus at the tip which in rest re- 

 ceives the apex of the anterior hp (d). Palpus long, curved downwards ; 

 1st and 2d joints short, 3d very long, 5th long, and 6th in the male elon- 

 gate pyriform without a hook ; spiny and hairy (d^). Cephalothorax cir- 

 cular or broadly oval behind, produced anteriorly. Legs very long and 

 very hairy, with a few spines especially on the tibia; 1st pair (Ji i), 9 times 

 the length of the thorax ; 2d and 4th pair, 7i times ; 3d pair, 6a times : 

 tarsus clawed. Abdomen cylindric with 2 long feelers, and short spinnerets. 



Tr. libratus. {Libratus, balanced; pensile appearance of insect when 

 at rest, />.) Cephalothorax brownish green posteriorly, castaneous an- 

 teriorly, with 2 irregular parallel black lines running from the posterior 

 intermediate eyes down the back, terminating half way by joining semi- 

 lunar patches which occupy the remainder, and which have 3 irregular pro- 

 cesses projecting outwards towards the origins of the legs ; internally they 

 are shaded off, but rather defined behind the middle thoracic point, which is 

 marked by a minute short line ; beneath reddish brown, darker towards the 

 edges, but with a brighter spot opposite the origin of each leg. — Abdomen 

 greenish ; lighter in the middle, which is bounded by 2 longitudinal dark 



