ART. 8 CRUSTACEANS FROM WESTERN ATLANTIC TATTERSALL 7 



from L. typicus in possessing a subdorsal spine directed straight 

 backwards on the posterior margin of the sixth abdominal somite, 

 at the base of the telson on each side. These spines are really present 

 in L. typicus but are not nearly so well developed or so prominent 

 as in L. spinosus. 



Distribution. — Ortmann (1906) first made known the occurrence 

 of this species off the coast of North America, recording it from off 

 the coasts of North and South Carolina, the Gulf of Mexico and Key 

 West, though Smith (1881) had earlier noted the presence of 

 Lopliogaster off the coasts of New England, without naming the 

 species. These are the only records, with which I am acquainted, 

 from this region of the Atlantic Ocean. The Bache specimen was 

 captured at a point intermediate between the Carolina stations and 

 Key West of Ortmann's records. 



2. LOPHOGASTER SPINOSUS Ortmann 



Lophogaster spinosus Ortmann, 1906, p. 26, pi. 1, figs, la, 16. — Hansen, 

 1910, p. 14.— ZiMMER, 1914, p. 382. 



Occurrence. — Station 10195, 100-0 m., 1 young specimen, 9.5 mm. 

 long from the tip of the rostrum to the end of the telson. 



Remarlcs. — Although the specimen is so small, it exhibits all the 

 characters distinctive of the species as compared with L. typicus. 

 The median spine of the rostral plate is hardly as long as in the type- 

 specimen and this fact was also noted by Zimmer in young specimens. 

 On the other hand the posterolateral prolongations of the carapace 

 are proportionally longer than in the type, extending backward 

 almost to the level of the posterior margin of the third abdominal 

 somite. The antennal scale has nine teeth, including the terminal, 

 on the outer margin. The telson has altogether eight pairs of lateral 

 spines, including the large terminal pair, and has five teeth on the 

 pectinate apical portion. The postero-lateral free corners of the 

 third, fourth, fifth, and sixth abdominal pleura are acute and pro- 

 duced into prominent spines, less produced in the third pleura than 

 in the others but in all cases much more produced than in L. typicus, 

 in which the pleura of the third somite are without spines. 



Distribution. — The type-specimen was taken at 30° 47' 30" N., 

 79° 49' W., north of the Bahamas. The BacJie specimen is from a 

 locality rather to the northeast of the Bahamas but not very far 

 from the type-locality. Zimmer, however, has recorded the species 

 from the South Atlantic, midway between South America and South 

 Africa. From the fact that the present specimen was caught in a 

 midwater townet, it seems probable that L. spinosus, like L. typicus, 

 is pelagic in the post-larval and young stages. In this connection 

 it is to be noted that one of Zimmer's specimens was caught in a 

 townet at only 10 meters. The Bache specimen shows no traces of 

 pectinations on the rostral plate or abdominal pleura. 



