REPORT ON THE CRUSTACEA MACRURA. 493 



First pair of antennae biflagellate, short. 



Second pair having a long, slender flagellum, and a scaphocerite that reaches beyond 

 the peduncle of the first pair. 



Oral appendages as in Crangon. 



Second pair of gnathopoda four-jointed, the ultimate joint but slightly longer than 

 the penultimate and terminating in an obtuse point. 



First pair of pereiopoda robust, long and subchelate, like those of Crangon, which it 

 much resembles. Second pair of pereiopoda short, feeble and simple, terminating in a 

 small obtuse and rudimentary dactylos. Third pair long, slender and styliform ; on the 

 ventral surface of the pereion between this pair of appendages there stands a long, 

 slender, spine-like tooth. Posterior two pairs of pereiopoda robust, subequal and 

 simple. 



The branchiae consist of seven pairs arranged as in the genus Pontophilus, namely, 

 six pleurobranchiae and one podobranchia, disposed as shown in the following table : — 



PleurobranchiaB, . . . ...111111 



Arthrobranchia?, . . . 



Podobranchia?, . . . 1 



Mastigobranchia?, . . . 1 r 



li i k 1 in n o 



Development. — The brephalos appears to be further advanced than the Zoea stage. 

 I only know it as an advanced embryo extracted from the ovum, but even then it has the 

 carapace largely developed, the pleon well formed, the ophthalmopoda large and 

 orbicular, the antennae assuming their distinguishing character, and the pleopoda in a 

 budding condition. The whole form is suggestive of the genus Nebalia. 



Geographical Distribution. — This genus was first described by Professor Owen from 

 specimens taken in the Arctic regions. It has since been taken in the Atlantic, off the 

 western coast of America, as far south as 40° of north latitude, and Stimpson records it 

 from the Siberian Seas. 



Sabinea septemcarinata (Sabine) (PI. LXXXIX. fig. 2 ; PI. XC. fig. 1). 



Crangon septemcarinata, Sabine, Suppl. to Parry's First Voyage for the Discovery of a North- 

 West Passage, p. ccxxxvi, pi. ii. figs. 11-13, 1824. 



„ „ Ross, Appendix to Parry's Polar Voyage, p. 203, 1824. 



Sabinea septemcarinata, Owen, Appendix to Ross's Narrative of a Second Voyage in Search of a 



North- West Passage, p. lxxxii, 1835. 

 Crangon septemcarinatus, Milne-Edwards, Hist. Nat. Crust., vol. ii. p. 343, 1837. 

 Sabinea septemcarinata, Sars, Forhandl. Vidensk. Selsk. Christ., 1858, p. 125, 1859. 



„ „ Stimpson, Proc. Acad. Nat. Sci. Philad., p. 94, 1860. 



„ „ Sidney Smith, Trans. Connect. Acad., vol. v. pt. 1, p. 57, pi. xi. fig. 5. 



„ tarsii, Sidney Smith, loc. tit., p. 59, pi. xi. fig. 6. 



