47 Grufit, 
CRUSTACEA. 
existence of a bent-forward portion of the oesophagus and of a proven- 
triculus, and the simultaneous presence of reticulated and frontal eyes. 
The most important differences from the rest of Crustacea are the exist- 
ence of only one pair of prsaorajl members, the want of special mandibles, 
and the homonomy and small number of the cephalo-thoracic members. 
Neither the knowledge of its development nor its palaeontology yields 
any fact which could enable us to connect it more closely with other 
orders of the Crustacea, or with the Arachnida ; the fossil Eurypteridoi 
have, indeed, some relations to Limulus, chiefly in the thoracic members, 
but no real near affinity can be maintained. Klassen und Ordnungen des 
Thierreichs, y. Arthropoda, pp. 1089 -1136 (chiefly 1123-1130) pis. xxxvi.- 
xxxix. 
H. Woodward, in the last part of his monograph of British fossil 
Crustacea, gives a general account of our knowledge of recent Limulus, 
containing Owen’s paper on the anatomy of L. polyphemus, taken from 
Tr. L. S. xxviii. fl872] pp. 459-506, with 3 pis., pp. 186-210, pis. xxxiv.- 
xxxvi. He treats of its mouth and replacement of lost appendages, 
pp. 210-212 ; its spawning, the eggs being fecundated by the male after 
their deposition in the sand, from Lockwood’s observations, p. 212 ; its 
embryology, chiefly from Packard [Zool. Bee. viii. p. 195] pp. 213-221 ; 
its zoological position, with special reference to the views of Dohrn and 
Owen, urging the relations with the Crustacea, and especially Pterygotus, 
pp. 221-232 ; and the geographical distribution of the recent species, 
from Milne-Edwards (1873) p. 233. 
E. Ray Lankester states that the spermatozoids of Limulus are 
actively motile, and concludes that this genus ought to be placed among 
the Arachnida, forming there a special sub-class, Branchiopulmonata \ 
Q. J. Micr. Sci. xviii. pp. 453 & 454. 
A. Agassiz has observed that young specimens of Limulus swim, and 
rest very often on their backs. Am. J. Sc. (3) xv. p. 75, also in Ann. 
N. H. (5) i. p. 183. 
