Longitude between Cambridge and Salt Lake City.-Not corrected for personal equation. NOTE.-Telegraph repeaters were used at Buffalo, Chicago, Omaha and Cheyenne. ngitude Determinations across the Continent, January and February, 1869. (Final results.) Personal Equations. Dean odfellow Dean Station. Cambridge, Mosman = +08·11 Davidson Salt Lake, San Francisco, +0.180 Dean, 0.000 +0.180 To be applied to the clock corrections of the respective stations to reduce them to Dean's standard. To correct the differences of longitude for personal equation, e have: Cambridge Time 66 66 Omaha Time 66 Cambridge San Francisco Time=0.070 Omaha 66 Salt Lake =-0.020 66 =-0.180 ence of Longitude. mission time. Corrected differ- Double trans h. m. s. 8. h. m. s. 1 39 15-159 +130 1 39 15-289008 336±015 ambridge to Salt Lake maha to Salt Lake ambr'ge to S. Francisco 3 25 7.260 2 43 4.257 +110 2 43 4367+008 591019 1 1 3 49-081 -.020 1 3 49.061008 260±016 - 070 1 45 52-094 alt Lake to S. Francisco 0 42 3.024 -200 -180 3 25 7·190007 817014 483023 0 42 2.844+008 242±016 ART. LVII.- Notice of the Invertebrata dredged in Lake Sue in 1871, by the U. S. Lake Survey, under the direction of C. B. Comstock, S. I. Smith, naturalist; by S. L SMITH A. E. VERRILL. (Published by permission.) DURING the explorations in Lake Superior, mentioned in last number of this Journal (page 373) the following spe were obtained, together with a number of minute forms, have not been determined. A full account of the expedition, with descriptions of species collected, will be published in the official report et expedition. RADIATA. Hydra carnea Agassiz. A beautiful Hydra, agreeing Ayer's description of this species, was very abundant a eastern end of St. Ignace, upon rocks along the shore and the surface, frequently completely covering quite large s where they were protected from the direct sunlight, an. also brought up in many of the dredgings from 8 to 148 fa In 32 fathoms, Neepigon Bay, and in 59 fathoms, off Sinn Harbor, it was brought up in abundance from a soft clayer tom. In the deep dredgings, it frequently came up na bottom of the clay in the dredge, and was evidently not c while the dredge was near the surface. MOLLUSCA. Limnæa. A species allied to L. disidiosa Say, was a among Cladophora in 8 to 13 fathoms on the south side Ignace Island. Physa heterostropha Say. In the cove at the eastern St. Ignace, in 4 to 6 fathoms, and young specimens, in fathoms, at the locality with the Limnoa just mentione Physa vinosa Gould. A very young specimen, appare this species, in 6 to 8 fathoms among the Slate Islands Planorbis parvus Say. ath side of St. Ignace. Common in 8 to 13 fathoms on the Valvatu sincera (Say sp.). Abundant with the last species, 8 to 13 fathoms, and also, in 4 to 6 fathoms, in the cove at è eastern end of the same island. Sphærium sp. nov.? Among the Slate Islands, in 6 to 8 homs. A single young specimen of another species of Sphæm was found, in 8 to 13 fathoms, on the south side of St. ace. Pisidium Virginicum Bourguignat. On the south side of St. ace, 8 to 13 fathoms. Pisidium abditum Haldeman. With the last species, in 8 to fathoms, and also, in 4 to 6 fathoms, in the cove at the tern end of the same island. Pisidium compressum Prime. In the cove at the eastern end St. Ignace, 4 to 6 fathoms. Pisidium sp. nov. A small, semi-translucent species, the same found by Dr. Stimpson in Lake Michigan, was brought up nearly every dredging. It was common in the cove at the tern end of St. Ignace, on sandy and muddy bottom, in 4 to thoms, and abundant among Cladophora, in 8 to 13 fathoms, the south side of that island; among the Slate Islands, in 6 8 and 12 to 14 fathoms; at 13 to 15 fathoms on a sandy tom in Simmon's Harbor; near Copper Harbor, in 17 fathoms, r sand; in 32 fathoms, very soft clayey mud, in Neepigon ́; off Copper Harbor, in 62 fathoms, and north of Keweenaw nt, in 82 fathoms, soft reddish clayey mud and sand; and 11 the deep dredging down to 159 fathoms. WORMS. umbricus lacustris Verrill, sp. nov. About 1.5 inches long, in diameter. Body round, distinctly annulated. Head t, conical, obtusely pointed. Setæ spine-like, strongly ed, acute, arranged two by two, those of each pair close ther. Color reddish brown. outh side of St. Ignace, among Cadophora, 8 to 13 fathoms. enuris abyssicola Verrill, sp. nov. Worm slender, attenuated eriorly, about 30 of an inch long, 03 in diameter anteriorly. y composed of about 28 segments, those of the posterior elongated; those of the anterior half shorter, separated by it constrictions. Cephalic lobe short, subconical, rounded ont. Mouth large, semi-circular. Intestine slender, monili1, containing sand. Anus terminal, with three or four slight S. Setæ in four, fan-shaped fascicles on each segment, comcing at second segment behind the mouth. The two ral fascicles are separated by a space equal to about twice length of the setæ, of which there are five or six in each cle; the sata are simple, acute, slightly curved, equal to about one-sixth the diameter of the body. The lateral fas contain three to five somewhat shorter and straighters setæ. One specimen appeared to have four minute ocelli the upper side of the head. Off Copper Harbor, 17 fathoms, sand; off Simmon's Ha 60 fathoms; and on the line from the Slate Islands to Stannard Rock, fourth haul, 159 fathoms. Sanuris limicola Verrill, sp. nov. Worm more slender : the preceding, attenuated posteriorly, composed of abo segments. Length about 33 of an inch, diameter 02. Ce lobe blunt, conical. Setæ in four fascicles upon each seg six to eight in each fascicle anteriorly, four or five poster The setæ in all the fascicles are relatively long, slender, c-- | and acute. Two tortuous red blood vessels pass along the testine, forming a loop at each segment. Intestine moni On the line between the Slate Islands and Stannard E fourth haul, 159 fathoms. Chirodrillus, gen. nov. Allied to Sanuris, but with si shaped fascicles of setæ upon each segment, two of are ventral, two lateral, and two sub-dorsal; setæ in the ve and lateral fascicles four to nine, simple, acute, slender, cr | like an italic f; those of the dorsal fascicles, stouter and curved, three to six in each fascicle. Intestine wide, som moniliform. Anus terminal, large. Chirodrillus larviformis Verrill, sp. nov. Body rather and not very slender, cylindrical, obtuse at both ends, dis annulated, composed of about 38 rings. Length about an inch; diameter 05. Cephalic lobe short, conical, mouth large, semi-circular beneath. Ventral fascicles dit near together, with about five setæ, which are rather s simple, acute, little curved; lateral fascicles with five a setæ of similar form and size; sub-dorsal ones similar. preserved in alcohol, the body is usually curved ventral a simple coil. Color, when living, translucent whitish, it slightly greenish. A thickened smooth zone commences the 10th setigerous ring, occupying the space of aber segments. Off Copper Harbor, 17 fathoms, sand; off Simmon's E 59 fathoms, clayey mud. Chirodrillus abyssorum Verrill, sp. nov. Sub-ev thicker anteriorly, distinctly annulated, composed of ab segments. Length 25 of an inch; diameter about 02. C lobe short, conical, obtuse, mouth large, semi-circular. T fascicles with eight or nine setæ anteriorly, five or six pos The setæ are long, slender, acute, strongly curved, those inferior side of the fascicles nearly twice as long upper side; setæ of the lateral fascicles five or six, 8 nearly as long as those of the ventral ones, and similar in |