354 Dr. H. Woodiuard — On a new Branchiopod 



swimming-feet (doubtless also brauchigerous) ; the body is terminated 

 by a pointed telson or tail- spine, giving origin to a pair of shorter 

 lateral lamelliB from its base. 



I have no hesitation in referring this unique specimea to the 

 Branchiopoda. 



In Sir Ray Lankester's Treatise on Zoology, 1909, ch. ii, p. 29, 

 Dr. W. T. Caiman, writing on the Crustacea, divides the sub-class 

 Branchiopoda as follows : — 



Order 1. Anostraca — Branchinecta, Artemia, Chirocephalus, etc. 



,, 2. NoTOSTEACA — LepiduTUs, Apus, etc. 



,, 3. CoNCHOsTRACA — Estheria, etc. 



,, 4. Cladocera — Daphnia, etc. 



Sub-order 1. Calyptomera (tribe 1, Ctenopoda ; tribe 2, Anomopoda). 

 ,, 2. Gymnomera (tribe 1 , Onychopoda ; tribe 2, Haplopoda). 



In this sub-class the carapace may form a dorsal shield, as in Apus, 

 Lepidunis, etc. (the oSTotostraca) ; or a bivalved shell, as in JEstheria, 

 etc. (the Conchostraca) ; or it may be entirely absent, as in tbe 

 specimen before us and in Artemia, Chirocephalus, Brachineda, etc. 

 (the Anostraca). 



Fig. 1. Chirocephalus diaphanus (living freshwater). Enlarged three times 

 nat. size. These animals always swim upon their backs. Keproduced 

 (reduced) from Baird's Nat. Hist. British Entoniostraca, 1850. 



The range in time of the sub-class Branchiopoda is very great. 

 Professor C. D. Walcott has figured an ^^^a-like form of Crustacean, 

 Protocaris Marshii, in his " Fauna of the Lower Cambrian, or Olenellus 

 zone" (Tenth Ann. Rep. U!S. Geol. Surv., pi. Ixxxi, fig. 6). 

 Professor T. Rupert Jones has figured Estheria memhranacea (Pacht) 

 (Pal. Soc. Foss. Estherice, 1862, p. 14, pi. i, figs. 1-7) from the Old 

 Red (Devonian) of Caithness. Dr. Friedrich Goldenberg, in his Fauna 

 Sarcepontana Fossilis, 1873 ("Die Fossilen Thiere aus der Stein- 

 kohlenformation von Saarbriicken "), described and figured (Heft i, 

 p. 23, Taf. i, fig. 15) six somewhat doubtful-looking segments 

 which he attributes to Branchipus, and names Branchipusites 

 anthr acinus. The following is a translation from Dr. Goldenberg' s 

 paper : — 



Of this animal eigbt segments are to be seen in profile ; but of these, tbe 

 first and last are very imperfect. Tbe middle segments are also imperfectly 

 preserved, so that one can only find indications of their segmentation. Tbe 

 lateral appendages (side-pieces or epimera), of which six are present, are pretty 

 perfect in their natural connexion, and have much resemblance to tbe lamellar 

 branchial feet of a Bra^ichijnis. Their anterior margin is somewhat incurved ; 



