33 (Fig. 1.8) has a peculiar spectrum, which was classified as O9.7 Iabpe. It 
 33  presents emission at H{gamma} and all the lines appear peculiarly weak for 
 33  a supergiant star.
 35 (Fig. 1.9) is a widely studied object because it is the optical counterpart 
 35  to the X-ray source LMC X-1. Hutchings et al. (1983ApJ...275L..43H) found 
 35  it to be an O7 star with a binary period of approximately 4 days; they 
 35  also suggested that the secondary could be a black hole. It was later 
 35  classified as O7-9 III by Pakull (1984, IAU Symp., 108, 317) and 
 35  Bianchi & Pakull (1985A&A...146..242B). We find a type of O8(f)p, where the
 35  peculiarity refers to the reversed HeII {lambda}4686 emission. For this 
 35  reason it has been associated with the Onfp class by N.R. Walborn et al.
 35  (2009, in preparation), of which the HeII profile is a defining 
 35  characteristic, 35  although in this object the absorption lines are not 
 35  broadened, and the HeII profile may be related to the X-ray binary system.
 37 (Fig. 1.4) was classified as O8 here, although Conti & Fitzpatrick 
 37  (1991ApJ...373..100C) classified it as O3-O6, based on the presence of 
 37  HeII {lambda}{lambda}4200, 4541, 4686 absorption lines and possible 
 37  NIII {lambda}{lambda}4634-40-42 emission lines. The stellar HeI absorption 
 37  lines were obliterated by the very strong nebular emission lines in their 
 37  observation. For our classification we used mainly the ratios of 
 37  HeII {lambda}4541/HeI {lambda}4387 and HeII {lambda}4200/HeI {lambda}4144. 
 37  We also used the oversubtracted nebular [OIII] {lambda}4363 line present 
 37  in the final spectrum to estimate the nebular oversubtraction (see Bosch 
 37  et al. 1999A&AS..137...21B). We found a correction of less than 15%, 
 37  which indicates that the stellar HeI {lambda}4471 absorption is indeed 
 37  deeper than HeII {lambda}4541. In addition, the CIII {lambda}4070 
 37  absorption blend is present. All of these considerations indicate that the 
 37  spectral type of Star 37 must be closer to O8. Unfortunately, our 
 37  wavelength coverage for this object did not allow us to check for the 
 37  presence of NIII emission, as suspected by Conti & Fitzpatrick 
 37  (1991ApJ...373..100C). The luminosity class could not be assessed due 
 37  to the lack of the HeII {lambda}4686 line.
 38 (Fig. 1.17) is a B3 supergiant that at one time was also a candidate for 
 38  identification with LMC X-1. Fortunately, the weak HeII {lambda}4686 
 38  emission seen in high S/N digital data was not visible in the early 
 38  observations, or this misidentification would have been considered 
 38  definite! Ramsey et al. (2006ApJ...641..241R) have clearly shown that this 
 38  anomalous emission feature actually arises in an unusual high-ionization 
 38  nebulosity in the field, which may be related to the X-ray source.
 39 (Fig. 1.8) was classified as O9.7 Ia+pe. It is certainly an unusual 
 39  spectrum, probably related to the Ofpe/WN9 or WNL class. See, for 
 39  comparison, the spectrum of HD 152408 (Walborn et al. 2000PASP..112...50W).
 39  However, these characteristics have not been seen before at such a late 
 39  O type.
 41 (Fig. 1.1) is the hottest star we have found among the sample. It was 
 41  classified as O3 Vz((f*)), although the z nature (HeII {lambda}4686 
 41  absorption stronger than other He lines, possibly an indicator of 
 41  subluminosity and extreme youth) is marginal. 
 41  NIII {lambda}{lambda}4634-40-42 and NIV {lambda}4058 are clearly detected 
 41  in emission and NV {lambda}{lambda}4604-20 absorption lines are also 
 41  present. SiIV {lambda}{lambda}4089-4116 seem to be in emission but the 
 41  features are not conspicuous.
 93 (Fig. 1.10) was classified as BN0 Iabp due to enhanced NIII and deficient 
 93  C and O lines, characteristic of OBN stars (Walborn 1971ApJ...164L..67W, 
 93  1976ApJ...205..419W). The additional peculiarity is the presence of P Cygni
 93  profiles at H{gamma} and HeI lines.
179 (Fig. 1.10) was classified as B Iae P Cyg. The P Cygni features can be seen 
179  in H{epsilon} and H{delta}, but not in H{gamma} which is totally in 
179  emission. This object is quite similar to HD 87643 (Walborn & Fitzpatrick 
179  2000PASP..112...50W), which belongs to the group of Iron Stars, of which 
179  {eta} Carinae is the most famous member.
 54 54, 70, 76, 107, and 112 (Fig. 1.20) show either anomalously broad or 
 54  asymmetric profiles in their absorption lines, suggesting a possible 
 54  binary nature. The wavelength resolution does not allow us to reliably 
 54  analyze radial velocity information. Higher resolution spectra would be 
 54  needed to assess the possibility of these being SB2 stars.
 70 54, 70, 76, 107, and 112 (Fig. 1.20) show either anomalously broad or 
 70  asymmetric profiles in their absorption lines, suggesting a possible 
 70  binary nature. The wavelength resolution does not allow us to reliably 
 70  analyze radial velocity information. Higher resolution spectra would be 
 70  needed to assess the possibility of these being SB2 stars.
 76 54, 70, 76, 107, and 112 (Fig. 1.20) show either anomalously broad or 
 76  asymmetric profiles in their absorption lines, suggesting a possible 
 76  binary nature. The wavelength resolution does not allow us to reliably 
 76  analyze radial velocity information. Higher resolution spectra would be 
 76  needed to assess the possibility of these being SB2 stars.
107 54, 70, 76, 107, and 112 (Fig. 1.20) show either anomalously broad or 
107  asymmetric profiles in their absorption lines, suggesting a possible 
107  binary nature. The wavelength resolution does not allow us to reliably 
107  analyze radial velocity information. Higher resolution spectra would be 
107  needed to assess the possibility of these being SB2 stars.
112 54, 70, 76, 107, and 112 (Fig. 1.20) show either anomalously broad or 
112  asymmetric profiles in their absorption lines, suggesting a possible 
112  binary nature. The wavelength resolution does not allow us to reliably 
112  analyze radial velocity information. Higher resolution spectra would be 
112  needed to assess the possibility of these being SB2 stars.
 72 72, 82, and 151 (Fig. 1.9) belong to the Onfp category (Walborn
 72  1973AJ.....78.1067W). In their spectra, the broad emission in 
 72  HeII {lambda}4686 with absorption reversal can be observed (see the 
 72  Appendix). 
 82 72, 82, and 151 (Fig. 1.9) belong to the Onfp category (Walborn
 82  1973AJ.....78.1067W). In their spectra, the broad emission in 
 82  HeII {lambda}4686 with absorption reversal can be observed (see the 
 82  Appendix). Stars 72 and 82 are also denoted with "+" due to 
 82  SiIV {lambda}4116 emission; they also present CIII {lambda}4650 in 
 82  emission. A luminosity class cannot be inferred for these stars because 
 82  of the peculiar HeII {lambda}4686 profiles (N.R. Walborn et al. 2009, 
 82  in preparation).
151 72, 82, and 151 (Fig. 1.9) belong to the Onfp category (Walborn
151  1973AJ.....78.1067W). In their spectra, the broad emission in 
151  HeII {lambda}4686 with absorption reversal can be observed (see the 
151  Appendix). Stars 72 and 82 are also denoted with "+" due to
151  SiIV {lambda}4116 emission; they also present CIII {lambda}4650 in 
151  emission. A luminosity class cannot be inferred for these stars because 
151  of the peculiar HeII {lambda}4686 profiles (N.R. Walborn et al. 2009,  
151  in preparation).