24 Mr. E. J. Miers on the Squillidae. 



Squilla dvhia. 



Squilla mantis, Desm. Consid. Crust, p. 250, pi. xli. fig. 2 (1825), nee 



auctorum. 

 ? Squilla dubia, M.-Edwards, Hist. Nat. Crust, ii. p. 522 (1837); 



Gibbes, Proc. Amer. Assoc, vi. p. 200 (1850). 

 ? Squilla rubrolineata, Dana, Crust. U.S. Expl. Exp. xiii. p. 618, 



pi. xli. fig. 2 (1852) ; v. Martens, Arcbiv f. Naturg. xxxviii. p. 144 



(1872). 



This species is nearly allied to S. mantis ; but the rostral 

 plate is narrowed toward and rounded at its distal end and is 

 without a median keel. The lateral processes of the first exposed 

 thoracic segment are straight and acute, those of the two fol- 

 lowing segments obliquely truncated and with the postero- 

 lateral angles only subacute. The terminal postabdominal 

 segment has the median carina and the marginal spines and 

 spinules considerably thickened ; the punctures of the upper 

 surface are obsolete; but on either side of the median carina 

 there is a longitudinal series of very small granules or tuber- 

 cles, between the submedian spines of the posterior margin 

 there are usually from four to six rounded tubercles or teeth, 

 and between these and the first lateral marginal spines three 

 or four on each side ; the marginal spines of the dactyli of the 

 large raptorial limbs are rather small, and the first or proximal 

 spine is even occasionally obsolete. The distal prolongation 

 of the base of the uropoda ends in two spines ; and the inner 

 spine bears a well-marked rounded tooth on its outer margin. 



Hah. East coast of North, Central, and South America. 



In the collection of the British Museum there is an adult 

 male from St. Domingo (collected by Mr. Tweedie), another 

 from Belize, Honduras (Rev. J. Gregg) , and three others with- 

 out special indication of locality (from the Haslar Hospital 

 collection). 



Gibbes's specimens were from Charleston Harbour, U. S., 

 where this species appears to be rare. Von Martens records 

 numerous specimens collected by Dr. Gundlach at Cuba, 

 and gives some interesting particulars respecting the varia- 

 tion in the number of the marginal spines of the dactyli 

 of the raptorial limbs, and of the marginal spines of the ter- 

 minal postabdominal segment &c. Dana records it from Rio 

 de Janeiro. 



This is one of the few species of Squilla in which the spines 

 of the dactyli of the raptorial limbs appear to vary in number. 

 According to Von Martens, the dactyli are more frequently five- 

 than six-spined ; in only one of the Museum specimens, how- 

 ever, are they fewer than six-spined ; and in this example the 

 dactylus of one side lias five, and of the other four spines. 



