Boone, Crustacea, Cruises of "Eagle" and '*Ara," 1921-28 59 



Genus : ptychogaster a. Milne Edwards. 



Ptychogaster spimfera A. Milne Edwards. 



Plate 15. 



Type: A female taken by the ''Blake," at station 167, Guadeloupe, 

 is designated by Dr. Milne Edwards as type and is deposited in the 

 National Museum d'Histoire Naturelle, Paris. 



Distribution: West Indies and Caribbean Sea at depths ranging 

 from 123 to 366 fms. Taken by the "Blake" at Fredickstadt, 180 fms., 

 Guadeloupe, 183 fms., Santa Lucia, 154 fms., Grenadines, 127 fms., 

 Caricou, 163 fms., Barbados, 124 fms., and by the "Pawnee," north of 

 Glover Reef, Caribbean Sea, 366 fms. The "Ara" specimen taken 

 seven miles southwest of Alligator Reef, Florida, establishes the north- 

 ernmost record for the species. 



Material examined : One specimen dredged seven miles southwest of 

 AUigator Reef, Florida, in 150 fms., March 30, 1926. 



Color : In life this species is a rich, semitranslucent old ivory. 



Technical description : Rostrum slightly longer than the eye, slen- 

 der, acuminate, upward- and forward-directed, with the inferior lat- 

 eral margins lightly carinate, these carinae continuous on the superior 

 orbital margin. Carapace 13 mm. long from base of rostral spine to 

 posterior margin, rostrum 3 mm. long; carapace 9 mm. maximum 

 width across the median region. The precervical region is elevated, 

 convex ; the cervical groove is deep ; there are a pair of acuminate up- 

 pointing teeth, placed subdistally, one behind each orbit ; behind each 

 of these spines are two smaller, widely spaced spinules; behind and 

 diagonally in line with this large spine are two more shorter spines ; 

 there are three medium-sized spinules subequally spaced in the median 

 line of the precervical region ; there is also a large, subdistal spine on 

 the hepatic region. The median postcervical region is elevated and 

 bears a median row of three subequally spaced spines, continuing the 

 row on the precervical region ; on either side of the median row there 

 are about eight spinules, forming two irregular, longitudinal series, the 

 upper of which terminates in a high, acute spine on the posterior mar- 

 gin of the carapace. The median lateral part of the postcervical region 

 has a longitudinal row of four or five long spines, on either side of 

 which are a number of irregularly spaced spinules ; the linea ano- 

 murica is sharply defined and below and subparallel to it is a longi- 



