No. 2390. DRAGON-FLY NAIADS FROM TEXAS— KENNEDY. 597 



they ascribe the species australis, cornutus, furcifer, pallidus, sub- 

 apicalis, submedianus, villosipes, and whedoni. The only species of 

 this group known to be regional are subapicalis and submedianus. 

 I think we can ascribe these naiads to one or the other of these species 

 with little doubt. They were collected from a sluggish stream or 

 sloughs such as are inhabited by members of this group. 5 



The following is a description of this naiad: Head small, body very 

 flat, abdomen lanceolate, broadest at segments 4 and 5, tapering 

 abruptly at segment 8 to the narrow segments 9 and 10. 



Head triangular, the eyes noticeably small, though surrounded by 

 a large eyelike area. (See fig. 10.) Labium as in furcifer, 6 with the 

 middle lobe but slightly rounded and bearing a single median tooth 

 among the long needlelike scales. (See figs. 9 and- 11.) Lateral 

 lobes with their apices but slightly incurved and bearing six obliquely 

 truncated teeth besides the end tooth. (See fig. 9.) 



Abdomen with a low, rounded, and interrupted mid-dorsal keel 

 extending from the apex of segment 3 to the middle of segment 9 

 and on segments 8 and 9 terminating in a short rounded point. 

 Segments 6 to 9 with lateral spines, short on segments 6 to 8, but 

 those on 9 nearly as long as segment 10. Apex of abdomen upturned; 

 segment 8 slightly more than one and a half times as long as segment 

 7. Segment 10 longer than wide, one-half as long as 9. Anal 

 appendages less than segment 10 in length. (See fig. 12.) 



This naiad differs from those of australis, cornutus, and furcifer in 

 the great length of the lateral spines on segment 9 ; it differes from the 

 naiads of pallidus and villosipes in that the abdomen is noticeably 

 suddenly contracted at segment 8. Thus this naiad combines the 

 shape of the abdomen in australis, cornutus, and furcifer with the long 

 spines on segment 9 found in pallidus 7 and villiosipes. 



GOMPHUS (STYLURUS) PLAGIATUS Selys. 



A single immature naiad 25 mm. long; its wing cases reaching 

 to the middle of segment 2. 



This subgenus has had the following species ascribed to it by Wil- 

 liamson 8 : Amnicola, scudderi, plagiatus, spiniceps, and notatus. To 

 these we can now add olivaceus and intricatus. The naiad of notatus 

 is unknown. This naiad agrees, except in its immaturity, with a 

 reared plagiatus in the writer's collections. 



DROMOGOMPHUS SPOLIATUS (Hagan). 



A single naiad 25 mm. long. This is immature with the wing cases 

 reaching barely beyond segment 1. 



• Muttkowski and Whedon, Gomphus cornutus Tough, Bull. Wis. N. H. Soc., vol. 13, p. 99. 1915. 

 « Walker, The nymph of Gornphus furcifer, Can. Ent., Dec. 1904. 



' Hagen's description (Trans. Amer. Ent. Soc., vol. 12) does not agree with Cabot's figure in that the 

 figure has short spines on segment 9. 

 » The subgenus Stylurus, Trans. Amer. Ent. Soc., vol. 18, p. 207, 1901. 



