260 Part III. — Twelfth Annual Report 



Pseudanthessius sauvagei, Canu. 



1891. Pseudanthessius sauvagei, Canu (10 b.), p. 481. 



1892. Pseudanthessius sauvagei, Canu (11), p. 243, pi. xxv. 

 figs. 1-17. 



1894. Pseudanthessius sauvagei, T. and A. Scott (31), p. 146. 



Habitat. — Off St Monans. Rare. 



Want of time has prevented the preparation of drawings of this 

 interesting species for the present paper. 



Pseudanthessius gracilis, Claus. 



1889. Pseudanthessius gracilis, Claus (13), vol. viii. p. 344, pi. iv. 

 figs. 1-7. 



1893. Pseudanthessius gracilis, T. and A. Scott (32), p. 241, pi. 

 xii. figs. 15--20. 



Habitat. — Off Musselburgh, among material collected in 1891. Some 

 specimens were also taken in the Moray Firth among Filograna implexa. 



One of the Moray Firth specimens measured 1'3 mm. (^gth of an inch). 

 The anterior antennae are shorter than the first body segment, and seven- 

 jointed ; the third and the last joints are the shortest. The proportional 

 lengths are shown by the formula: — 



17 . 20 • 8 • 14 • 16 • 13 • 9 • 

 1-2.3-4-5-6-7' 



The third joint of the posterior antennae is very small. The anterior 

 foot-jaws are slender, and armed with a few strong teeth on the upper 

 edge. A plumose seta springs from the inner edge near the base of 

 the second joint. Posterior foot-jaws three-jointed. Second joint some- 

 what dilated, and bearing a short stout spine. The last joint very 

 small, and armed with two terminal spines. Inner branches of the 

 fourth pair of thoracic feet one-jointed, scarcely reaching to the end of 

 the second joint of the outer branches, and armed with two dagger-shaped 

 spines at the truncate apex. There is a small hook-like process near the 

 middle of the inner margin. Fifth pair small, sub-quadrate, and furnished 

 at the apex with an elongate dagger-like spine and a plain seta. Caudal 

 stylets equal to about twice the length of the last abdominal segment. A 

 small seta springs from near the middle of the outer margin of each 

 stylet in addition to the terminal setae. 



This species differs from Pseudanthessius thorellii (B. and R.), with 

 which it is closely allied, in the form of the anterior foot-jaws in the 

 proportional length of the inner branches of the fourth pair of thoracic 

 feet, and in the form of the abdomen. 



Family Ascomyzontid^e. 



Genus Dermatomyzon, Claus (1889). 



[Cyclopicera, Brady (in part)]. 



Dermatomyzon gibber um, T. and A. Scott. (PI. X. figs. 26-34.) 



1894. Dermatomyzon gibberum, T. and A. Scott, p. 144, pi. ix. 

 figs. 10-14. 



Description.— Female. Length, *5 mm. (-^ of an inch). Cephalo-thorax 

 broadly ovate, or pear-shaped. Abdomen very short ; its length, including 

 that of the stylets, is scarcely equal to one-fourth of the length of cephalo- 

 thorax. Anterior antennae stout, seventeen-jointed. The second basal joint 



