120

Monte Video

1832

Chara seen flowing upwards & downwards.— The axillæ of the branches are verticillate with pointed cylinders, in these the circulation was evident, but very obscure: Novemb: 20th M: Video.

Hybernation of animals July 26th.- Aug. 19th. From finding Cassida, Crysomela, Curculionidous, Heteromerous, Lamellicorns, Carabidous beetles, & Epeira amongst spiders, under stones: from Vaginulus & land shells with a membrane over the mouth being in same site; from finding Bufo & Lacerta half torpid; it is clear animals are now hybernating.— Considering the high temperature, this is curious.— From 276 observ: made at 2 hours intervals during 23 days from July 27 to August 19th (both inclusive), mean temp is 58°.4.— Mean hottest day 65°.5 do. Coldest day 45°.8

The lowest point the Thermometer fell to was 41°.5; it occasionally in middle of the day rose to 69° or 70°.—

At (P 113) there are observations on the subject at Bahia Blanca & compared to those made at Monte Video.—

Gen: Observ: Monte Video July 26 to Aug. 19th. Birds are abundant in the plains & are brilliantly coloured.— Starlings, Thrushes, Shrikes, Larks & Partridges are the commonest.— Snipes here frequently rise & fly high up in great circles; in their flight, as they descend, they make that peculiar buzzing noise, which the few which breed in England are known to do.— On the sand-banks on the coast are large flocks of Rhynchops; these birds are generally supposed to be the inhabitants of the Tropics

121

Monte Video

1832

Gen: Observ: Monte Video July 26 to Aug. 19th. Every evening they fly out in flocks to the sea & return to the beach in the morning.— I have seen them at night, especially at Bahia Blanca, flying round a boat in a wild rapid irregular manner, something in same manner as Caprimulgus does.— I cannot imagine what animals they catch with their singular bills.—

The water of the Rio Plata at Monte Video is generally brackish, it is even sometimes fresh enough to drink.— It is not inhabited by many animals; a small Turbo6 & a Mytilus are nearly the only shells.— The occurrence of one of the Balanidæ Creusia in quite fresh water is curious, for details see notes attached to (323 in Cat: for Spirits). On the shore, the genera Plagusia & Grapsus are exceedingly abundant.— indeed they are nearly the only Brachyures which I have seen between M. Video & Bahia Blanca.— On the beach are also great numbers of minute Crust. Amphipod:— which here assume the place which Ligia10 takes in the Tropics.—

Amongst Arachnida by far the greatest proportion belong to Lycosa11.— I found Mygalus & Dysdera under stones & Segestria abundant in crevices of rock.— Scorpio & Gonoleptes are very abundant under stones.— In November an Epeira with bright colour is abundant in every situation.— The Entomology is chiefly characterised by, as compared to Brazil, by the (a) great increase of Carabidous beetles: also by the comparative absence of the Orthopterous insects, which perform so essential part in the latter.—

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(a) Amongst the Mammalia, the case is reversed; the carnivorous animals are as much more abundant in the intertropical regions than in the temperate, as the Carabidous amongst insects are in the latter compared to the former climate.—

122

1832

Crust: Branchiopod Cyclops 478 Decemb 1st.— South of Cape Corrientes, Patagonia.

Body composed of 7 pieces.— The anterior one case is rather narrower, convex, rounded anteriorly & projecting over base of antennæ. in front it terminates in a doubly pointed or forked rostrum, this projects downwards & gives the appearance of a sucking beak to the animal.— the posterior lateral part ends on each side in a point, projecting beyond line of body. In shape this resembles some of the Cyclops: 2nd & 3rd segments are wider & longer & cover the body; 4th, 5th, 6th, 7th form the abdomen: the 7th is excised & ends abruptly.— Body cylindrical.— case horny elastic.— Beyond the last segment, there is (as in Cyclops) a narrow rounded tail, 4 jointed; extremity bifid; on each division are about 5 pair of setæ.— Within the tail, there was a pulsating org vessel.— Eyes, 2, seated on each side of the curved beak, rounded very distinct; Inferior to & between these, are approximate antennæ; which will be described presently. Mouth in its situation is pectoral & not produced; it is obscure.— the mandibles [illeg] are flat plates with 6 teeth, the 2 inner ones largest:— They precisely partly resemble those figured by Desmarets of Apus:— Tongue oblong, rounded at extremity; Maxillæ & Palpi doubtful:

Independent of the Antennæ, there are 10 pair of articulated organs: (1st) stem simple, bifid at extremity, with bunches of setæ on each; also a small external branch with setæ.— these are situated before the mouth; & perhaps compose correspond to