THE OLFACTORY ORGANS OF DIPTERA 471 
TABLE 3—Continued 
NUMBER OF PORES 
teres 
ON dots 
FAMILY NUMBER AND NAME OF SPECIES Lariat 
Legs | Wings ats | Pores 
39. Sarcophaga plinthopyga Wied.....} 174 | 198 | 474 | 846 
40. Sarcophaga lambens Wied..?......| 170 | 204 | 534 | 908 
Sarcophagidae.. {| 41. Sarcophaga helicis Towns....‘....| 179 | 218 | 564 | 961 
ADE SALE OP NASA SP ces sys woo, succd. siaielack + = 180 | 194 | 474 | 848 
eds eSarcophaga: SPs). 5.) y02s a yeSseo ton 186 | 202 | 518 | 906 
(| 44. Olfersia americana © Leach...... 168 154 | 304 | 626 
Hipnoeectae 45. Melophagus ovinus 9 L.......... 162) |) Avs set, 162 
‘* || 46. Lipoptena depressa o Say........| 144 | D75} 200 | 419 
|| 47. Hippobosea struthinionis Jansen! 180 | 167 | 442 | 789 
Nycteribiidae..... 48. Nycteribia bellardii ~ Rondani..| 178) A | F44 | 222 
Variation J 90— 00—| 00—| 162— 
Pais Ot ry OA ERC Re ey CaCl ED, Ca Ch 'S Dutt CHOI OH an Se Ee REM eat od \ 391 408 | 871 (1550 
* For explanation of letters A to F, see p. 468. 
Structure of pores in Musca domestica 
The preceding pages deal with the disposition of the olfactory 
pores, and now a discussion of their anatomy will be given. 
a. Kxternal structure. As already stated, the pores in groups 
nos. 16 and 17 on the halteres (fig. 3) have been called Hicks’ 
organs, and since their structure is like that of those on the legs 
and wings, all of these pores may be regarded as belonging to the 
Hicks’ type. Since their anatomy does not differ materially 
from that of those in the other orders of insects, discussed in 
other papers by the writer, a reference to figures 4 to 15 may 
suffice at this place. t 
Under a high-power lens the scalpel groups (nos. 14 and 18) 
and the basal group (no. 15) look somewhat as shown in figures 
16 and 17. They may be compared with the Hicks’ type (nos. 
16 and 17). It is to be noted that the scalpel group no. 14 
consists of 11 rows and no. 18 of 10 rows. From a superficial 
view the rows appear to be flat, but sections will show that the 
pores are linked together and stand in ridges, projecting far 
above the surrounding integument. The summit of each ridge is 
beautifully sculptured, and’ a row of stout hairs (fig. 16, Hr') 
