Mr. C. Spence Bate on the British Diastylidse. 455 



The next succeeding pair of limbs (fig. 14) homologize with 

 the (so-called) second pair of thoracic legs in the Macroura, 

 Each agrees closely in character with the preceding, but differs 

 in details by the increased size of the coxae, the shortness of the 

 joints succeeding the basal, and the very great length of the 

 penultimate articulation of the legs : like the two preceding sets 

 of limbs, it is furnished with a palpe or secondary appendage. 

 Moreover, in the female a scale-like appendage, the fouet of 

 Milne-Edwards, is attached to this, the one preceding and the 

 next succeeding pairs of legs, forming by their mutual overlapping 

 the incubatory pouch, in which the e^g is nourished, and the 

 embryo cherished, and the larva carried until it assumes the form 

 of the adult animal, when it leaves the parent to seek its exist- 

 ence as a self-providing animal. 



The three next succeeding homologize with the three pos- 

 terior pairs of legs in the Decapoda, and are developed in one 

 form (fig. 15). The first joint or coxa appears not to be so closely 

 associated with the segment of the body as those belonging to the 

 anterior legs. The second joint is long, the third short, the 

 fourth long, and the two next intermediate ; the last joint ap- 

 pears to be represented by a stout jointed hair. 



Appendages are attached to the two next succeeding segments 

 of the body, in the male only, these being the first two segments 

 of the abdomen; they must therefore homologize with the 

 styliform processes in the males of the Decapoda which are 

 known to be intromittent organs, and probably answer the same 

 purpose in these creatures. 



The three succeeding segments are unfurnished with append- 

 ages in both sexes ; but the next, the penultimate, supports a 

 pair of a form peculiar to the family. They consist each of a 

 long basal joint, armed with a single row of spinules upon the 

 inner margin, and a pair of unequal terminal styliform processes 

 slightly fringed with cilia. This pair of appendages, with the 

 pointed terminal segment or telson, form the caudal appendage 

 or tail of the animal. 



The general structure of the integumentary tissues is slight : 

 the cell-character of the original formation is readily apparent 

 beneath the microscope, with a few granules of lime deposited in 

 each. The colour of the animal is stated by Mr. Harry Goodsir, 

 who took them in the Frith of Forth, as of a beautiful bright 

 straw colour inclining to yellow. I have never seen any alive, 

 but have received specimens from the Moray Frith from a 

 highly esteemed correspondent, the Rev. Geo. Gordon ; also from 

 St. Ives, where it has been dredged by my friend Geo. Barlee, 

 Esq., who also dredged a single specimen with mature larvae off 

 the Isle of Arran. From Falmouth I have received it from my 



