256 



Part ITT. — Thirteenth Annual Report 



that is the only loch among those described in the present paper in which 

 it was observed ; its pectinate post-abdominal claw (PI. X. fig. 10) appears 

 to be a distinctive character. 



Ceriodaphnia (?) laticaudata, P. E. Mtiller (PI. X. figs. 11-14). This 

 Ceriodaphnia, which appears to be of rare occurrence in Possil Marsh — 

 the only loch in which it was observed — may belong to the comparatively 

 common species Ceriodaphnia rotunda (Straus), but the figures of that 

 species in C. L. Herrick's Crustacea of Minnesota shows the end of the 

 post-abdomen to be evenly and boldy rounded, whereas the post-abdomen 

 of the Possil Marsh specimens is sub truncate and angular (fig. 13). The 

 few specimens obtained in Possil Marsh all agreed very closely in the form 

 of the post-abdomen with the one figured. 



Ceriodaphnia, sp. A. (PI. X. figs. 15-17). This is a form from 

 Bardowie Loch, near Glasgow, which may be Ceriodaphnia quadrangula 

 (O. F. Mtiller), but the form of the post-abdomen differs somewhat from 

 the post-abdomen of that species. It is considerably smaller than that of 

 the last species. 



Ceriodaphnia, sp. B. (PI. X. figs. 18, 19). This Ceriodaphnia is from 

 Scadowa Loch, North Uist. I am uncertain as to the species it belongs 

 to. The post-abdomen is considerably narrower than that of Ceriodaphnia 

 (?) laticaudata, and at the end it slopes more gradually and evenly down- 

 wards towards the claw, and in this respect it differs from the post- 

 abdomen of Ceriodaphnia, sp. A. 



Daphnia Jardinii, Baird (PI. X. figs. 20, 21). Figs. 20 and 20a 

 show two different forms of the head of this species from the same locality 

 — St German's Loch. The posterio-distal angle of the head is more 

 produced in fig. 20a than in the other specimen. 



Note. — The drawings of Cladocera in Plate X. have been prepared by 

 my daughter, Christina M. Scott. The drawings of the Copepoda are by 

 my son, Andrew Scott, fisheries assistant, Liverpool. 



DESCRIPTION OF THE PLATES. 

 Plate IX. 



Eurytemora clausii (Hock). 

 Fig. 1. Fifth pair of thoracic feet — female, . 



x 200 diameters. 



Attheyella Macandrewaz, n. sp. 



Fig. 2. Female — lateral view, 



Fig. 3. Antennule — female, . 



Fig. 4. Antenna, 



Fig. 5. Mandible and palp, . 



Fig. 6. Maxilla, . . 



Fig. 7. Anterior foot-jaw, 



Fig. 8. Posterior foot-jaw, 



Fig. 9. Foot of first pair of swimming feet, 



Fig. 10. Foot of fourth pair, . 



Fig. 11. Foot of fifth pah-, 



Fig. 12. Last abdominal segments and caudal stylets, 



106 diameters. 

 506 



506 „ 

 506 



506 „ 

 506 



506 „ 

 506 



380 „ 



506 



190 



