150 Unnrrsity of Texas Bulletin 



deep, ends in one point, and is funnel-shaped. The fourth auxihary 

 lobe, which is also on the umbilical wall, is quite insignificant and only 

 a slight notch, still shallower and smaher than the third one. 



The median saddle of the siphonal lobe is slightly notched at its 

 top by a shallow indentation and very little constricted near its base. 

 The external saddle is very slightly bent over toward the median sad- 

 dle and well constricted near the base. The first lateral saddle is 

 similar to the external but constricted only on its outer side, while 

 the inner one is nearly straight; the second lateral saddle is somewhat 

 asymmetrical, the inner side being constricted while the outer one 

 forms a straight line. It is a little broader than each of the preceding 

 ones. The first auxiliary saddle is broader and lower than the other 

 three; the second auxiliary is still more insignificant, the highest 

 point lying well over to the inner side; the third auxiliary is on the 

 umbilical wall, very low and small, but symmetrical. 



The internal suture (pi. VII, fig. 60, 61) is very characteristic. The 

 broad antisiphonal lobe is divided into three parts by two long and 

 slender saddles inclined toward each other. The middle branch is 

 lanceolate and much deeper than the lateral ones; these are asym- 

 metrical, curved and end in a point which lies near the inner side. The 

 first lateral lobe is slightly asymmetrical and bifid, the inner point 

 being stouter but shorter than the outer one. The second 

 lateral lobe is nearly asymmetrical and ends in one sharp 

 point. It is narrower in its upper part than in the middle. 

 The first auxiliary lobe is very asymmetrical, showing a very 

 long inner point and only a slight bulging at the outer side. It 

 is shorter and narrower than the first two and in its general outline 

 is funnel-shaped. The internal saddles are all high, entire, and 

 rounded at the top, and the first three are constricted below the middle. 

 Their height decreases slightly from the first to the third ; this latter 

 one is also much narrower than the first two. The first auxiliary 

 saddle is extremely broad but low and asymmetrical. It has about 

 the width of the first and second lateral together witlrthe intervening- 

 second lateral lobe. The greatest part of the first auxiliary saddle 

 still lies on the internal side of the whorl, but a portion of its outer 

 flank is on the umbilical wall. 



