12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO7 



if specimens of tyrannus from the southern part of the range, as from 

 Florida, were compared, as they have larger heads and longer fins 

 than northern material. 



A lectotype designated. — As Goode did not designate a type, I 

 have selected a specimen (U.S.N.M. No. 129797) approximately 

 180 mm. (caudal imperfect) in total length and 145 mm. in standard 

 length as lectotype. This specimen is from a lot quite certainly 

 examined by Goode, as already stated. 



Source of the data and their presentation. — The following list of 

 proportions and enumerations are based on the eight specimens al- 

 ready listed, which vary from 165 to 180 mm. in total length, and 

 from 126 to 147 mm. in standard length. The range in the percent of 

 standard length of the parts measured is given first in each instance 

 followed by the proportion based on the lectotype, and then the pro- 

 portion in the standard length or in the head is enclosed in paren- 

 theses. The enumerations are given in the same order. 



Some proportions and eiiunierations. — Head 29 to 30, 29 (3.3 to 

 3.85, 3.45 in standard length), its depth 26 to 27.5, 26 (3.6 to 3.84, 

 3.8) ; depth of body 35 to 38, 36 (2.6 to 2.85, 2.8) ; anal base 17.5 to 

 ^9> 17-5 (5-25 to 5.7, 5.7) ; lower lobe of caudal 22 to 25, 25 (4.0 to 

 4.4, 4.0) ; depth of caudal peduncle 9.6 to 10.5, 9.8 (2.8 to 3.0, 2.9 in 

 head) ; eye 5.4 to 6, 5.4 (4.7 to 5.4, 5.25 in head) ; snout 6.4 to y.^, 

 7-3 (3-9 to 4.6, 3.9 in head) ; interorbital (bone) 6.2 to 7.0, 7.0 (4.1 

 to 4.7, 4.1 in head) ; maxillary 12 to 13, 12 (2.2 to 2.4, 2.4 in head) ; 

 mandible 15.5 to 16, 15.5 (1.8 to 1.9, 1.85 in head) ; pectoral fin 13.5 

 to 16, 14.5 (1.8 to 2.2, 2.0 in head) ; axillary appendage of pectoral 

 8.0 to 9.4, 8.9 (3.0 to 3.8, 3.2 in head). Dorsal rays 20 or 21, 21 ; 

 anal rays 21 or 22, 21 ; pectoral rays 17; scales, oblique series cross- 

 ing middle of side, 47 to 53, 48 ; vertical series between tip of pectoral 

 and base of ventral 5 to 7, 6 ; modified scales in a series in front of 

 dorsal fin 35 to 39, 39; ventral scutes 31 to 33, 33; gill rakers on 

 lower limb of first arch 112 to 127, 124; vertebrae 48 (enumerated in 

 I specimen). 



The lectotype (fig. 2) has only the shoulder spot. However, one 

 specimen with it has a rather definite row of smaller dark spots below 

 and behind the shoulder spot, indicating that auxiliary spots, at least 

 sometimes, are present in this species. 



A parallel comparison of B. tyrannus and B. brevicaudata. — The 

 principal differences between tyrannus and brevicaudata are shown in 

 the following parallel comparison, wherein only specimens of about 

 equal size from the same general vicinity were considered. 



