160 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 5 



Squilla hancocki, new species 



Distribution: Known from 25 fathoms off Petatlan Bay, Mexico, 

 from Tangola-Tangola Bay, Mexico, 15-20 fathoms, and from Cape 

 San Francisco, Ecuador, 20 fathoms, muck bottom. 



Type: The largest of 4 females from off Petatlan Bay (Hancock 

 Exped. Sta. 264-34) has been selected as the type (U.S.N.M. No. 

 76074). It measures in median length, exclusive of the rostrum, 60 mm., 

 the carapace 13.2, the rostrum 2. This species is named for Captain Allan 

 Hancock, a generous patron of science and a true and good friend of 

 those who have had the great pleasure of going exploring with him. 



Description: A species in general appearance and markings very 

 like S. tiburonensis (== var. B. of S. panamensis Bigelow). Surface of 

 carapace and abdomen smooth and shining. The anterior width of the 

 carapace is a little more than half its median length exclusive of the 

 rostrum; the median carina before the cervical groove is not bifurcate 

 at either end ; the intermediates continue anteriorly to the anterior mar- 

 gin. The rostral plate is more or less subquadrate, slightly tapering, and 

 broadly rounded distally; in tiburonensis the rostral plate, though distally 

 rounded off, is elongated triangular with the lateral margins a little 

 convex. In the latter species the rostral plate is margined with color, in 

 hancocki it is all colored except for a relatively small semicircular area 

 at the middle of the basal or proximal margin. The corneae are set 

 obliquely on their stalks. The raptorial dactylus, as in the other pana- 

 mensis relatives, is armed with 6 teeth. 



The lateral spine of the 5th thoracic somite extends more or less 

 straight out to the side, much as in typical S. panamensis, with but slight 

 forward inclination ; in S. tiburonensis the corresponding spine is distally 

 noticeably turned forward. The lateral margins of the posterior lobes of 

 the 6th and 7th thoracic somites more or less subacute, in any case with 

 tips or lateral extensions with only slight if any posterior inclination : in 

 tiburonensis these posterior lobes are sharply and acutely pointed, and 

 these spinous processes are definitely posteriorly directed. 



Of the submedian carinae of the abdomen only those on the 6th somite 

 are posteriorly spined; the (3rd?), 4th, 5th, and 6th intermediates are 

 spined, 3-6 laterals inclusive, and all the marginal carinae. 



The denticles of the telson number 3-5, 7-10, 1. In this respect, the 

 telson resembles that of tiburonensis, and in other respects also it resem- 

 bles that species, as well as other related panamensis forms ; yet it differs 



