90 SEVENTH REPORT. 



cal, and since more than 50 per cent of the hutlerii thus far recorded have jE^ temporals 

 and only 25 per cent have j^ the number given for hutlerii, it seems probable that 

 Y^ is the normal number of temporals for hutlerii. 



PARIETAL SCUTA. 



Cope describes the parietal scuta of hrachystoma as " convex in outline and not con- 

 tracted posteriorly," and those of hutlerii with "external border abruptly contracted." 

 A glance at his own figures (Annual report of the Smithsonian Institute for 1898, pages 

 1031 and 1057) is sufficient to show how small the difference is, even in his three specimens, 

 and the Olivet specimens show that this character is too variable to be of value, while the 

 fact that in both cases the mouth is so short as to end under the posterior end of the parietals 

 tends strongly to show that the snakes are identical. 



SCALE ROWS. 



We quote Cope's words: "hrachystoma — Scales in nineteen series all keeled except 

 the inferior row which has a trace of a keel." "hutlerii — Scales in nineteen longitudinal 

 rows, the inferior one much the widest and keeled." It is evident that this is no difference. 

 The wide inferior row is characteristic of eutania and the keel of hutlerii is faint as in hrachy- 

 stoma. 



GASTROSTEGES. 



Brachystoma has 132 gastrosteges and hutlerii 144 according to Cope. Mr. Ruthven 

 gives the number as 140 for hutlerii and the mean of the twenty-nine specimens shows 

 that this is about right, the average showing approximately 139. This in itself proves 

 nothing except that the gastrosteges of hutlerii are fewer than Cope supposed. It is 

 worthy of note, however, that 132 gastrosteges {hrachystoma) is not an unusually small 

 number for hutlerii. Ruthven's list shows a hutlerii with only a 131 and Clark's shows 

 one with 133, numbers respectively one below and one above the 132 of hrachystoma. In 

 addition there are several hutlerii with 134 or 135 136 gastrosteges so that the small 

 number in hrachystoma cannot in any way distinguish it from hutlerii. 



UROSTEGES. 



The number of urosteges (72) seems large but is by no means abnormal, in hutlerii, espec- 

 ially when the important matter of sex is taken into consideration. Ruthven's list shows a 

 hutlerii with 71 (urosteges) and two with 68 and 67 respectively. Mr. Sperry's investiga- 

 tions of Eutaenia ('03 p. 175-179) shows clearly that there is a very decided correlation be- 

 tween sex and the length percentage of tail and the number of urosteges. The males have 

 a larger number of urosteges and a correspondingly larger tail percentage. So marked 

 is this difference that sex can almost unfailingly be determined by these characters alone. 

 Cope's hrachystoma was doubtless a male, and although Mr. Ruthven has not tabulated 

 the sex of his hutlerii, the three mentioned as having a large number of urosteges :71, 68, 67) 

 are undoubtedly males as there tail per cent .shows. They are .236, .261 and .255 respective- 

 ly, an average of about .25. Cope's hrachystoma shows a tail per cent of .248. Bearing 

 these facts in mind it becomes evident that the 72 urosteges of hrachystoma, so far from 

 constituting a specific difference merely show that it is a normal hutlerii. 



COLORATION. 



Allowing for the fact that Cope's single hrachystoma was an alcoholis specimen and just 

 ready to shed its skin when captured, the general coloration of these snakes {hutlerii and 

 brachystoma is so much alike as to need no discussion. Two or three special points seem 

 to require mention, however. The median dorsal stripe covers exactly one and two half 

 rows of scales in both snakes, and its color is practical^ the same. Dr. Clark and Mr. 

 Ruthven, both of whom have examined a number of specimens {hutlerii) whereas Cope 

 had only two, agree that Cope's statement that the lateral stripe of hutlerii covers the second 

 and third scale rows is not correct. The lateral stripe really includes (Dr. Clark '03, p. 85 

 "all the third row. the lower half of most of the fourth row and the upper half of many 

 in the second row." 



Cope says of hrachystoma: "The absence of spots on the gastrosteges distinguishes it 

 from most of the sub-species of E. sirtalis;" and of hutlerii: "With a vertical black spot 



