REPOET ON THE STOilATOPODA. 45 



very imperfectly described, and it has unfortunately been lost ; but his description and 

 the figures which were afterwards published by Milne- Edwards, show such a close resem- 

 blance to Lysioaquilla excavatrix, n. sp., described below, that there can be no doubt of 

 their very intimate relationship or of the importance of the difi"erences between them and 

 Dana's Lysiosquilla inornata, upon which this author based his genus I/ysiosquilla, which 

 has broad triangular eyes, large antennary scales, filiform appendages to the last three 

 thoracic legs, and the larva of the closely related Lysiosquilla maculata has a short rostrum 

 and postero-lateral spines; while Lysiosquilla (Coro7iis) excavatrix has small subcylindrical 

 eyes, minute antennary scales and uropods, dilated appendages to the last three thoracic 

 limbs, and the rostrum and postero-lateral spines of its larva are very long. 



Notwithstanding these important difi"erences the various species agree in many 

 featuies, such as the presence of numerous spines on the dactyle, and of very few between 

 the submedian and intermediate spines of the telson, in the loose articulation of the wide 

 flat hind body, and the absence of dorsal carina. They cannot be arranged in two 

 divergent groups, and it is impossible to draw any abrupt line between them. There 

 can, therefore, be no doubt of the propriety of including them in one genus, as Miers ^ 

 does, retaining Dana's term Lysiosquilla for all of them. 



The higher and lower forms stand in precisely the same relation to each other as do 

 Squilla and Chloridella, and there is also a most suggestive similarity in the character of 

 the differences. In fact it is almost as difficult to detect generic difierences between 

 Coronis and Chloridella as between the latter and Squilla, or between Coronis and 

 the higher Lysiosquilla. 



The two genera Squilla and Lysiosquilla are divergent stems from a common stalk, . 

 and while the higher forms are quite distinct, the resemblance between the lower forms 

 is no more than we should expect. 



While there can be no doubt that all the very wide Erichthi with a deep infolded 

 carapace are Lysiosquilla larvae, we cannot state with confidence that all Lysiosquillse 

 have larvae of this type, for there are no strongly marked and constant differences between 

 the L/ysioerichihiis and the Gonerichthus and Pseuderichthus, and it is not impossible 

 that some of the narrow elongated Pseuderichthi may be Lysiosquilla larvae. 



In some of the Lysiosquillae, and possibly in aU of them, there are marked secondary 

 differences between the sexes. 



Lysiosquilla maculata (Fabricius) (PI. X. figs. 1-7). 



The Challenger collection includes four specimens of this well-known and -w-idely 

 distributed species; one full-grown male, No. 1, presented by the king of Amboina ; 

 a half-grown male, No. 3, from Amboina, and a mature male and female, No. 2, from 



' Miers, On the Sqviillidse, p. 3. 



