PACKARD ON NEW PIIYLLOPOD CRUSTACEA. 



177 



Female. — Very closely allied to the female 8. texanus, though as a rule 

 somewhat smaller, the eyes being decidedly smaller. The second an- 

 tenuffi are a little, sometimes much, longer in proportion, and are mu- 

 cronate, as in the other species. The ovisacs are as in S. texanus, but 

 the eggs are much smaller in proportion. The caudal appendages do not 

 differ materially from those of the males, nor from those of the females 

 of iS'. texanus. 



Length of males, IG"^"" ; females, 12-18™°^. About fifty of each sex 

 examined, although several hundred were casually looked over, with- 

 out finding any that approached 8. texanus any nearer than has been 

 indicated. 



Ellis, Kans., in pools on the prairie, June 28, 29, September 27, and 

 October 10-22, Dr. L. Watson. A large number of half-grown males 

 and females occurred in June. The largest females, those measuring 18 

 millimeters in leugth, occurred October 22, the ovisacs filled with eggs 

 in some cases; in others, partially or entirely empty. The body was 

 soft and in such a state of preservation as to indicate that they were at 

 the point of dissolution. They were found associated with Thamno- 

 cephalus, Lymnetis, Esther ia., Eulimnadia., and Apus lucasanus. The tails 

 "were red, says Dr. Watson, and in some the bodies were blue. This re- 

 fers to those which were collected in June and early in July. " Those 

 found in October and early in November (the 6th) were pure white, and 

 the appendages to the tail seemed to me to be more divaricate than 

 those of summer, in which those appendages were of a red color." 

 While the males are easily distinguishable from those of *S'. texanus by 

 the much greater length and different style of branching of the second 

 antenuiB, as well as in the smaller frontal tubercle and the slenderer 

 caudal appendages, the females differ but slightly, but may still be dis- 

 tinguished by the smaller eyes and longer second autenuoe. This spe- 

 cies is dedicated to Dr. L. Watson, who has been 

 indefatigable in his exertions to get me specimens. 



Lepidurus couesii Pack. (American Naturalist, 

 ix, 1875, 311) (Fig. 16, dorsal and lateral view). — 

 Compared with L. productiis Bosc, of Europe, the 

 carapace is of the same proportion, being large, 

 broad, and leaving about five entire terminal seg- 

 ments exposed, including the telson. The deuticu- 

 lations on the hinder edge of the carapace are finer 

 than in the European species, and show a tendency 

 to become obsolete on the lower part of the incis- 

 ion. The eyes are slightly fuller, more prominent 

 than in L. prodnctns, and the interocular tubercle 

 is smaller. The muscular area of the carapace is 

 the same as in L. prodiictiis. There are usually 

 from ten to twelve spines on the penultimate segment, as in L. productus. 

 The chief <listiuction is in the very long spatulate telson, which is about 



12 BULL 



Fig. 



