MONOCEROS, or the Unicorn, lies south of Gemini and Canis Minor, north of Canis Major and Argo, east of Orion, and west of Hydra. It appears on the planisphere of Bartschius, published in 1624. According to Scaliger it is shown on an old Persian sphere. One of its stars, Fl. 22, is mentioned by Al-Sufi among the "extern" stars of Canis Major (No. 1). Another, Fl. 30, is given under Hydra ("Extern" No. 1) and Fl. 8, 13, and 15 are apparently referred to in Gemini. The star 15 Monocerotis is a little south of ξ Geminorum, and was measured 4·59 magnitude at Harvard. It was at one time supposed to be variable with a short period (about 3½ days), but this variation has not been confirmed. The spectrum is of the fifth type--with bright lines--a very rare type among naked-eye stars. It is a triple star (5, 8·8, 11·2: 2"·9, 16"·3) and should be seen with a 4-inch telescope. It has several other small companions, one of which (139°·2: 75"·7) has been suspected of variation in light. It was estimated 8½ by Main in 1863, but only 12 by Sadler in 1875. Observing it on March 28, 1889, with 3-inch refractor, I found it about one magnitude brighter than a star closely preceding, and estimated it 8 or 8½ magnitude. It is probably variable and should be watched. SCUTUM SOBIESKI.--This is, or was, a small constellation in the southern portion of Aquila, which was formed by Hevelius in 1660 in honour of the Polish hero Sobieski. Its principal stars, which lie south-west of λ Aquilæ, were mentioned by Al-Sufi and are referred to by him under that constellation. It contains a very bright spot of Milky Way light, which may be well seen in the month of July just below the star λ Aquilæ. Closely south of the star 6 Aquilæ is a remarkable variable star R Scuti (R.A. 18{h} 42{m}·2, S. 5° 49'). It varies from 4·8 to 7·8 with an irregular period. All the light changes can be observed with a good opera-glass. VULPECULA, the Fox.--This modern constellation lies south of Cygnus, north of Sagitta and Delphinus, east of Hercules, and west of Pegasus. It was formed by Hevelius in 1660. One of its stars, 6 Vulpeculæ, is mentioned by Al-Sufi in describing the constellation Cygnus. Closely north-west of 32 Vulpeculæ is the short-period variable T Vulpeculæ. It varies from 5·5 to 6·2 magnitude, and its period is 4·436 days. This is an interesting object, and all the changes of light can be observed with an opera-glass. LACERTA.--This little constellation lies south of Cepheus and north of Pegasus. Its formation was first suggested by Roger and Anthelm in 1679, and it was called by them "The Sceptre and the Hand of Justice." It was named Lacerta by Hevelius in 1690, and this name it still retains. Al-Sufi seems to refer to its stars in his description of Andromeda, but does not mention any star in particular. It brightest star Fl. 7 (α Lacertæ) is about the 4th magnitude. About one degree south-west of 7 is 5 Lacertæ, a deep orange star with a blue companion in a fine field.